Sidelink harq feedback for groupcast transmission

ABSTRACT

According to one embodiment of the disclosure, provided is a method by which a first device performs groupcast communication. The method comprises the steps of transmitting a PSCCH and a PSSCH to N receiving devices, and receiving at least one HARQ feedback for the PSSCH on the basis of M PSFCH PRB sets, wherein at least one PSFCH PRB set based on CS values differing from each other is set on the M PSFCH PRB sets on the basis that N is larger than M, and N and M are positive integers.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

This disclosure relates to a wireless communication system.

Related Art

Sidelink (SL) communication is a communication scheme in which a direct link is established between User Equipments (UEs) and the UEs exchange voice and data directly with each other without intervention of an evolved Node B (eNB). SL communication is under consideration as a solution to the overhead of an eNB caused by rapidly increasing data traffic.

Vehicle-to-everything (V2X) refers to a communication technology through which a vehicle exchanges information with another vehicle, a pedestrian, an object having an infrastructure (or infra) established therein, and so on. The V2X may be divided into 4 types, such as vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). The V2X communication may be provided via a PC5 interface and/or Uu interface.

Meanwhile, as a wider range of communication devices require larger communication capacities, the need for mobile broadband communication that is more enhanced than the existing Radio Access Technology (RAT) is rising. Accordingly, discussions are made on services and user equipment (UE) that are sensitive to reliability and latency. And, a next generation radio access technology that is based on the enhanced mobile broadband communication, massive Machine Type Communication (MTC), Ultra-Reliable and Low Latency Communication (URLLC), and so on, may be referred to as a new radio access technology (RAT) or new radio (NR). Herein, the NR may also support vehicle-to-everything (V2X) communication.

FIG. 1 is a drawing for describing V2X communication based on NR, compared to V2X communication based on RAT used before NR. The embodiment of FIG. 1 may be combined with various embodiments of the present disclosure.

Regarding V2X communication, a scheme of providing a safety service, based on a V2X message such as BSM (Basic Safety Message), CAM (Cooperative Awareness Message), and DENM (Decentralized Environmental Notification Message) is focused in the discussion on the RAT used before the NR. The V2X message may include position information, dynamic information, attribute information, or the like. For example, a UE may transmit a periodic message type CAM and/or an event triggered message type DENM to another UE.

For example, the CAM may include dynamic state information of the vehicle such as direction and speed, static data of the vehicle such as a size, and basic vehicle information such as an exterior illumination state, route details, or the like. For example, the UE may broadcast the CAM, and latency of the CAM may be less than 100 ms. For example, the UE may generate the DENM and transmit it to another UE in an unexpected situation such as a vehicle breakdown, accident, or the like. For example, all vehicles within a transmission range of the UE may receive the CAM and/or the DENM. In this case, the DENM may have a higher priority than the CAM.

Thereafter, regarding V2X communication, various V2X scenarios are proposed in NR. For example, the various V2X scenarios may include vehicle platooning, advanced driving, extended sensors, remote driving, or the like.

For example, based on the vehicle platooning, vehicles may move together by dynamically forming a group. For example, in order to perform platoon operations based on the vehicle platooning, the vehicles belonging to the group may receive periodic data from a leading vehicle. For example, the vehicles belonging to the group may decrease or increase an interval between the vehicles by using the periodic data.

For example, based on the advanced driving, the vehicle may be semi-automated or fully automated. For example, each vehicle may adjust trajectories or maneuvers, based on data obtained from a local sensor of a proximity vehicle and/or a proximity logical entity. In addition, for example, each vehicle may share driving intention with proximity vehicles.

For example, based on the extended sensors, raw data, processed data, or live video data obtained through the local sensors may be exchanged between a vehicle, a logical entity, a UE of pedestrians, and/or a V2X application server. Therefore, for example, the vehicle may recognize a more improved environment than an environment in which a self-sensor is used for detection.

For example, based on the remote driving, for a person who cannot drive or a remote vehicle in a dangerous environment, a remote driver or a V2X application may operate or control the remote vehicle. For example, if a route is predictable such as public transportation, cloud computing based driving may be used for the operation or control of the remote vehicle. In addition, for example, an access for a cloud-based back-end service platform may be considered for the remote driving.

Meanwhile, a scheme of specifying service requirements for various V2X scenarios such as vehicle platooning, advanced driving, extended sensors, remote driving, or the like is discussed in NR-based V2X communication.

SUMMARY OF THE DISCLOSURE

A technical problem of the present disclosure is to provide a method for communication between apparatuses (or terminals) based on V2X communication, and the apparatuses (or terminals) performing the method.

Another technical problem of the present disclosure is to provide a method for an apparatus that has performed groupcast transmission to receive at least one Hybrid Automatic Repeat Request (HARQ) feedback and the apparatus (or a terminal) for performing the same.

According to an embodiment of the present disclosure, a method for performing groupcast communication by a first apparatus may be provided. The method may include transmitting physical sidelink control channel (PSCCH) and physical sidelink shared channel (PSSCH) to N receiving apparatuses; and receiving at least one hybrid automatic repeat request (HARQ) feedback for the PSSCH based on M physical sidelink feedback channel (PSFCH) physical resource block (PRB) sets, wherein, at least one PSFCH PRB set based on different CS values is configured on the M PSFCH PRB sets based on that the N is bigger than the M, and wherein the N and the M are positive integers.

According to an embodiment of the present disclosure, a first apparatus for performing groupcast transmission may be provided. The first apparatus may include at least one memory storing instructions, at least one transceiver and at least one processor connecting the at least one memory and the at least one transceiver, wherein the at least one processor is configured to: control the transceiver to transmit physical sidelink control channel (PSCCH) and physical sidelink shared channel (PSSCH) to N receiving apparatuses, and control the transceiver to receive at least one hybrid automatic repeat request (HARQ) feedback for the PSSCH based on M physical sidelink feedback channel (PSFCH) physical resource block (PRB) sets, wherein, at least one PSFCH PRB set based on different CS values is configured on the M PSFCH PRB sets based on that the N is bigger than the M, and wherein the N and the M are positive integers.

According to an embodiment of the present disclosure, an apparatus (or chip(set)) controlling a first terminal may be provided. The apparatus includes at least one processor and at least one computer memory that is executably connected by the at least one processor and stores instructions, wherein, by the at least one processor executing the instructions, the first terminal: transmit physical sidelink control channel (PSCCH) and physical sidelink shared channel (PSSCH) to N receiving apparatuses, and receive at least one hybrid automatic repeat request (HARQ) feedback for the PSSCH based on M physical sidelink feedback channel (PSFCH) physical resource block (PRB) sets, wherein, at least one PSFCH PRB set based on different CS values is configured on the M PSFCH PRB sets based on that the N is bigger than the M, and wherein the N and the M are positive integers.

According to an embodiment of the present disclosure, a non-transitory computer-readable storage medium having instructions stored thereon may be provided. Based on the instructions being executed by at least one processor: physical sidelink control channel (PSCCH) and physical sidelink shared channel (PSSCH) are transmitted to N receiving apparatuses by a first apparatus, and at least one hybrid automatic repeat request (HARQ) feedback for the PSSCH is received by the first apparatus based on M physical sidelink feedback channel (PSFCH) physical resource block (PRB) sets, wherein, at least one PSFCH PRB set based on different CS values is configured on the M PSFCH PRB sets based on that the N is bigger than the M, and wherein the N and the M may be positive integers.

According to an embodiment of the present disclosure, a second apparatus for performing groupcast transmission may be provided. The second apparatus includes at least one memory storing instructions, at least one transceiver and at least one processor connecting the at least one memory and the at least one transceiver, wherein the at least one processor is configured to: control the at least one transceiver to receive PSCCH and PSSCH from a first apparatus, and control the at least one transceiver to transmit a first HARQ feedback for the PSSCH to the first apparatus on a first PSFCH PRB set, wherein the PSSCH is transmitted by the first apparatus to N receiving apparatuses including the second apparatus, wherein at least one HARQ feedback for the PSSCH is received by the first apparatus based on M PSFCH PRB sets, wherein the at least one HARQ feedback includes the first HARQ feedback, wherein, at least one PSFCH PRB set based on different CS values is configured on the M PSFCH PRB sets based on that the N is bigger than the M, wherein the first PSFCH PRB set is one PSFCH PRB set among the M PSFCH PRB sets, and wherein the N and the M are positive integers.

According to an embodiment of the present disclosure, sidelink communication between apparatuses (or terminals) may be performed effectively.

According to an embodiment of the present disclosure, an apparatus which have performed a groupcast transmission may receive at least one HARQ feedback effectively.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing for describing V2X communication based on NR, compared to V2X communication based on RAT used before NR.

FIG. 2 shows a structure of an NR system, in accordance with an embodiment of the present disclosure.

FIG. 3 shows a functional division between an NG-RAN and a 5GC, in accordance with an embodiment of the present disclosure.

FIG. 4A and FIG. 4B show a radio protocol architecture, in accordance with an embodiment of the present disclosure.

FIG. 5 shows a structure of a wireless frame of an NR, in accordance with an embodiment of the present disclosure.

FIG. 6 shows a structure of a slot of an NR frame, in accordance with an embodiment of the present disclosure.

FIG. 7 shows an example of a BWP, in accordance with an embodiment of the present disclosure.

FIG. 8A and FIG. 8B show a radio protocol architecture for a SL communication, in accordance with an embodiment of the present disclosure.

FIG. 9 shows a UE performing V2X or SL communication, in accordance with an embodiment of the present disclosure.

FIG. 10A and FIG. 10B show a procedure of performing V2X or SL communication by a UE based on a transmission mode, in accordance with an embodiment of the present disclosure.

FIG. 11A through FIG. 11C show three cast types, in accordance with an embodiment of the present disclosure.

FIG. 12 shows at least one HARQ feedback of N receiving terminals for PSSCH transmission of a transmitting terminal according to an embodiment of the present disclosure.

FIG. 13 shows at least one HARQ feedback of N receiving terminals for PSSCH transmission of a transmitting terminal according to another embodiment of the present disclosure.

FIG. 14 is a diagram for describing an example in which a PSFCH resource for HARQ feedback is configured.

FIG. 15 is a flowchart illustrating an operation of a first apparatus according to an embodiment of the present disclosure.

FIG. 16 is a flowchart illustrating an operation of a second apparatus according to an embodiment of the present disclosure.

FIG. 17 shows a communication system 1, in accordance with an embodiment of the present disclosure.

FIG. 18 shows wireless devices, in accordance with an embodiment of the present disclosure.

FIG. 19 shows a signal process circuit for a transmission signal, in accordance with an embodiment of the present disclosure.

FIG. 20 shows a wireless device, in accordance with an embodiment of the present disclosure.

FIG. 21 shows a hand-held device, in accordance with an embodiment of the present disclosure.

FIG. 22 shows a car or an autonomous vehicle, in accordance with an embodiment of the present disclosure.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the present specification, “A or B” may mean “only A”, “only B” or “both A and B.” In other words, in the present specification, “A or B” may be interpreted as “A and/or B”. For example, in the present specification, “A, B, or C” may mean “only A”, “only B”, “only C”, or “any combination of A, B, C”.

A slash (/) or comma used in the present specification may mean “and/or”. For example, “A/B” may mean “A and/or B”. Accordingly, “A/B” may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C” may mean “A, B, or C”.

In the present specification, “at least one of A and B” may mean “only A”, “only B”, or “both A and B”. In addition, in the present specification, the expression “at least one of A or B” or “at least one of A and/or B” may be interpreted as “at least one of A and B”.

In addition, in the present specification, “at least one of A, B, and C” may mean “only A”, “only B”, “only C”, or “any combination of A, B, and C”. In addition, “at least one of A, B, or C” or “at least one of A, B, and/or C” may mean “at least one of A, B, and C”.

In addition, a parenthesis used in the present specification may mean “for example”. Specifically, when indicated as “control information (PDCCH)”, it may mean that “PDCCH” is proposed as an example of the “control information”. In other words, the “control information” of the present specification is not limited to “PDCCH”, and “PDDCH” may be proposed as an example of the “control information”. In addition, when indicated as “control information (i.e., PDCCH)”, it may also mean that “PDCCH” is proposed as an example of the “control information”.

A technical feature described individually in one figure in the present specification may be individually implemented, or may be simultaneously implemented.

The technology described below may be used in various wireless communication systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and so on. The CDMA may be implemented with a radio technology, such as universal terrestrial radio access (UTRA) or CDMA-2000. The TDMA may be implemented with a radio technology, such as global system for mobile communications (GSM)/general packet ratio service (GPRS)/enhanced data rate for GSM evolution (EDGE). The OFDMA may be implemented with a radio technology, such as institute of electrical and electronics engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, evolved UTRA (E-UTRA), and so on. IEEE 802.16m is an evolved version of IEEE 802.16e and provides backward compatibility with a system based on the IEEE 802.16e. The UTRA is part of a universal mobile telecommunication system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is part of an evolved UMTS (E-UMTS) using the E-UTRA. The 3GPP LTE uses the OFDMA in a downlink and uses the SC-FDMA in an uplink. LTE-advanced (LTE-A) is an evolution of the LTE.

5G NR is a successive technology of LTE-A corresponding to a new Clean-slate type mobile communication system having the characteristics of high performance, low latency, high availability, and so on. 5G NR may use resources of all spectrum available for usage including low frequency bands of less than 1 GHz, middle frequency bands ranging from 1 GHz to 10 GHz, high frequency (millimeter waves) of 24 GHz or more, and so on.

For clarity in the description, the following description will mostly focus on LTE-A or 5G NR. However, technical features according to an embodiment of the present disclosure will not be limited only to this.

FIG. 2 shows a structure of an NR system, in accordance with an embodiment of the present disclosure. The embodiment of FIG. 2 may be combined with various embodiments of the present disclosure.

Referring to FIG. 2, a next generation-radio access network (NG-RAN) may include a BS 20 providing a UE 10 with a user plane and control plane protocol termination. For example, the BS 20 may include a next generation-Node B (gNB) and/or an evolved-NodeB (eNB). For example, the UE 10 may be fixed or mobile and may be referred to as other terms, such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), wireless device, and so on. For example, the BS may be referred to as a fixed station which communicates with the UE 10 and may be referred to as other terms, such as a base transceiver system (BTS), an access point (AP), and so on.

The embodiment of FIG. 2 exemplifies a case where only the gNB is included. The BSs 20 may be connected to one another via Xn interface. The BS 20 may be connected to one another via 5th generation (5G) core network (5GC) and NG interface. More specifically, the BSs 20 may be connected to an access and mobility management function (AMF) 30 via NG-C interface, and may be connected to a user plane function (UPF) 30 via NG-U interface.

FIG. 3 shows a functional division between an NG-RAN and a 5GC, in accordance with an embodiment of the present disclosure.

Referring to FIG. 3, the gNB may provide functions, such as Inter Cell Radio Resource Management (RRM), Radio Bearer (RB) control, Connection Mobility Control, Radio Admission Control, Measurement Configuration & Provision, Dynamic Resource Allocation, and so on. An AMF may provide functions, such as Non Access Stratum (NAS) security, idle state mobility processing, and so on. A UPF may provide functions, such as Mobility Anchoring, Protocol Data Unit (PDU) processing, and so on. A Session Management Function (SMF) may provide functions, such as user equipment (UE) Internet Protocol (IP) address allocation, PDU session control, and so on.

Layers of a radio interface protocol between the UE and the network can be classified into a first layer (L1), a second layer (L2), and a third layer (L3) based on the lower three layers of the open system interconnection (OSI) model that is well-known in the communication system. Among them, a physical (PHY) layer belonging to the first layer provides an information transfer service by using a physical channel, and a radio resource control (RRC) layer belonging to the third layer serves to control a radio resource between the UE and the network. For this, the RRC layer exchanges an RRC message between the UE and the BS.

FIG. 4A and FIG. 4B show a radio protocol architecture, in accordance with an embodiment of the present disclosure. The embodiment of FIG. 4A and FIG. 4B may be combined with various embodiments of the present disclosure. Specifically, FIG. 4A shows a radio protocol architecture for a user plane, and FIG. 4B shows a radio protocol architecture for a control plane. The user plane corresponds to a protocol stack for user data transmission, and the control plane corresponds to a protocol stack for control signal transmission.

Referring to FIG. 4A and FIG. 4B, a physical layer provides an upper layer with an information transfer service through a physical channel. The physical layer is connected to a medium access control (MAC) layer which is an upper layer of the physical layer through a transport channel Data is transferred between the MAC layer and the physical layer through the transport channel. The transport channel is classified according to how and with what characteristics data is transmitted through a radio interface.

Between different physical layers, i.e., a physical layer of a transmitter and a physical layer of a receiver, data are transferred through the physical channel. The physical channel is modulated using an orthogonal frequency division multiplexing (OFDM) scheme, and utilizes time and frequency as a radio resource.

The MAC layer provides services to a radio link control (RLC) layer, which is a higher layer of the MAC layer, via a logical channel. The MAC layer provides a function of mapping multiple logical channels to multiple transport channels. The MAC layer also provides a function of logical channel multiplexing by mapping multiple logical channels to a single transport channel. The MAC layer provides data transfer services over logical channels.

The RLC layer performs concatenation, segmentation, and reassembly of Radio Link Control Service Data Unit (RLC SDU). In order to ensure diverse quality of service (QoS) required by a radio bearer (RB), the RLC layer provides three types of operation modes, i.e., a transparent mode (TM), an unacknowledged mode (UM), and an acknowledged mode (AM). An AM RLC provides error correction through an automatic repeat request (ARQ).

A radio resource control (RRC) layer is defined only in the control plane. The RRC layer serves to control the logical channel, the transport channel, and the physical channel in association with configuration, reconfiguration and release of RBs. The RB is a logical path provided by the first layer (i.e., the physical layer or the PHY layer) and the second layer (i.e., the MAC layer, the RLC layer, and the packet data convergence protocol (PDCP) layer) for data delivery between the UE and the network.

Functions of a packet data convergence protocol (PDCP) layer in the user plane include user data delivery, header compression, and ciphering. Functions of a PDCP layer in the control plane include control-plane data delivery and ciphering/integrity protection.

A service data adaptation protocol (SDAP) layer is defined only in a user plane. The SDAP layer performs mapping between a Quality of Service (QoS) flow and a data radio bearer (DRB) and QoS flow ID (QFI) marking in both DL and UL packets.

The configuration of the RB implies a process for specifying a radio protocol layer and channel properties to provide a particular service and for determining respective detailed parameters and operations. The RB can be classified into two types, i.e., a signaling RB (SRB) and a data RB (DRB). The SRB is used as a path for transmitting an RRC message in the control plane. The DRB is used as a path for transmitting user data in the user plane.

When an RRC connection is established between an RRC layer of the UE and an RRC layer of the E-UTRAN, the UE is in an RRC_CONNECTED state, and, otherwise, the UE may be in an RRC_IDLE state. In case of the NR, an RRC_INACTIVE state is additionally defined, and a UE being in the RRC_INACTIVE state may maintain its connection with a core network whereas its connection with the BS is released.

Data is transmitted from the network to the UE through a downlink transport channel Examples of the downlink transport channel include a broadcast channel (BCH) for transmitting system information and a downlink-shared channel (SCH) for transmitting user traffic or control messages. Traffic of downlink multicast or broadcast services or the control messages can be transmitted on the downlink-SCH or an additional downlink multicast channel (MCH). Data is transmitted from the UE to the network through an uplink transport channel. Examples of the uplink transport channel include a random access channel (RACH) for transmitting an initial control message and an uplink SCH for transmitting user traffic or control messages.

Examples of logical channels belonging to a higher channel of the transport channel and mapped onto the transport channels include a broadcast channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH), a multicast traffic channel (MTCH), etc.

The physical channel includes several OFDM symbols in a time domain and several sub-carriers in a frequency domain. One sub-frame includes a plurality of OFDM symbols in the time domain. A resource block is a unit of resource allocation, and consists of a plurality of OFDM symbols and a plurality of sub-carriers. Further, each subframe may use specific sub-carriers of specific OFDM symbols (e.g., a first OFDM symbol) of a corresponding subframe for a physical downlink control channel (PDCCH), i.e., an L1/L2 control channel A transmission time interval (TTI) is a unit time of subframe transmission.

FIG. 5 shows a structure of an NR system, in accordance with an embodiment of the present disclosure. The embodiment of FIG. 5 may be combined with various embodiments of the present disclosure.

Referring to FIG. 5, in the NR, a radio frame may be used for performing uplink and downlink transmission. A radio frame has a length of 10 ms and may be defined to be configured of two half-frames (HFs). A half-frame may include five 1 ms subframes (SFs). A subframe (SF) may be divided into one or more slots, and the number of slots within a subframe may be determined in accordance with subcarrier spacing (SCS). Each slot may include 12 or 14 OFDM(A) symbols according to a cyclic prefix (CP).

In case of using a normal CP, each slot may include 14 symbols. In case of using an extended CP, each slot may include 12 symbols. Herein, a symbol may include an OFDM symbol (or CP-OFDM symbol) and a Single Carrier-FDMA (SC-FDMA) symbol (or Discrete Fourier Transform-spread-OFDM (DFT-s-OFDM) symbol).

Table 1 shown below represents an example of a number of symbols per slot (Nslotsymb), a number slots per frame (Nframe,uslot), and a number of slots per subframe (Nsubframe,uslot) in accordance with an SCS configuration (u), in a case where a normal CP is used.

TABLE 1 SCS (15*2^(u)) N^(slot) _(symb) N^(frame, u) _(slot) N^(subframe, u) _(slot) 15 KHz (u = 0) 14 10 1 30 KHz (u = 1) 14 20 2 60 KHz (u = 2) 14 40 4 120 KHz (u = 3) 14 80 8 240 KHz (u = 4) 14 160 16

Table 2 shows an example of a number of symbols per slot, a number of slots per frame, and a number of slots per subframe in accordance with the SCS, in a case where an extended CP is used.

TABLE 2 SCS (15*2^(u)) N^(slot) _(symb) N^(frame, u) _(slot) N^(subframe, u) _(slot) 60 KHz (u = 2) 12 40 4

In an NR system, OFDM(A) numerologies (e.g., SCS, CP length, and so on) between multiple cells being integrate to one UE may be differently configured. Accordingly, a (absolute time) duration (or section) of a time resource (e.g., subframe, slot or TTI) (collectively referred to as a time unit (TU) for simplicity) being configured of the same number of symbols may be differently configured in the integrated cells.

In the NR, multiple numerologies or SCSs for supporting diverse 5G services may be supported. For example, in case an SCS is 15 kHz, a wide area of the conventional cellular bands may be supported, and, in case an SCS is 30 kHz/60 kHz a dense-urban, lower latency, wider carrier bandwidth may be supported. In case the SCS is 60 kHz or higher, a bandwidth that is greater than 24.25 GHz may be used in order to overcome phase noise.

An NR frequency band may be defined as two different types of frequency ranges. The two different types of frequency ranges may be FR1 and FR2. The values of the frequency ranges may be changed (or varied), and, for example, the two different types of frequency ranges may be as shown below in Table A3. Among the frequency ranges that are used in an NR system, FR1 may mean a “sub 6 GHz range”, and FR2 may mean an “above 6 GHz range” and may also be referred to as a millimeter wave (mmW).

TABLE 3 Frequency Range Corresponding Subcarrier Spacing designation frequency range (SCS) FR1  450 MHz-6000 MHz 15, 30, 60 kHz FR2 24250 MHz-52600 MHz 60, 120, 240 kHz

As described above, the values of the frequency ranges in the NR system may be changed (or varied). For example, as shown below in Table A4, FR1 may include a band within a range of 410 MHz to 7125 MHz. More specifically, FR1 may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, and so on) and higher. For example, a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, and so on) and higher being included in FR1 mat include an unlicensed band. The unlicensed band may be used for diverse purposes, e.g., the unlicensed band for vehicle-specific communication (e.g., automated driving).

TABLE 4 Frequency Range Corresponding Subcarrier Spacing designation frequency range (SCS) FR1  410 MHz-7125 MHz 15, 30, 60 kHz FR2 24250 MHz-52600 MHz 60, 120, 240 kHz

FIG. 6 shows a structure of a slot of an NR frame, in accordance with an embodiment of the present disclosure.

Referring to FIG. 6, a slot includes a plurality of symbols in a time domain. For example, in case of a normal CP, one slot may include 14 symbols. However, in case of an extended CP, one slot may include 12 symbols. Alternatively, in case of a normal CP, one slot may include 7 symbols. However, in case of an extended CP, one slot may include 6 symbols.

A carrier includes a plurality of subcarriers in a frequency domain. A Resource Block (RB) may be defined as a plurality of consecutive subcarriers (e.g., 12 subcarriers) in the frequency domain. A Bandwidth Part (BWP) may be defined as a plurality of consecutive (Physical) Resource Blocks ((P)RBs) in the frequency domain, and the BWP may correspond to one numerology (e.g., SCS, CP length, and so on). A carrier may include a maximum of N number BWPs (e.g., 5 BWPs). Data communication may be performed via an activated BWP. Each element may be referred to as a Resource Element (RE) within a resource grid and one complex symbol may be mapped to each element.

Meanwhile, a radio interface between a UE and another UE or a radio interface between the UE and a network may consist of an L1 layer, an L2 layer, and an L3 layer. In various embodiments of the present disclosure, the L1 layer may imply a physical layer. In addition, for example, the L2 layer may imply at least one of a MAC layer, an RLC layer, a PDCP layer, and an SDAP layer. In addition, for example, the L3 layer may imply an RRC layer.

Hereinafter, a bandwidth part (BWP) and a carrier will be described.

The BWP may be a set of consecutive physical resource blocks (PRBs) in a given numerology. The PRB may be selected from consecutive sub-sets of common resource blocks (CRBs) for the given numerology on a given carrier.

When using bandwidth adaptation (BA), a reception bandwidth and transmission bandwidth of a UE are not necessarily as large as a bandwidth of a cell, and the reception bandwidth and transmission bandwidth of the BS may be adjusted. For example, a network/BS may inform the UE of bandwidth adjustment. For example, the UE receive information/configuration for bandwidth adjustment from the network/BS. In this case, the UE may perform bandwidth adjustment based on the received information/configuration. For example, the bandwidth adjustment may include an increase/decrease of the bandwidth, a position change of the bandwidth, or a change in subcarrier spacing of the bandwidth.

For example, the bandwidth may be decreased during a period in which activity is low to save power. For example, the position of the bandwidth may move in a frequency domain. For example, the position of the bandwidth may move in the frequency domain to increase scheduling flexibility. For example, the subcarrier spacing of the bandwidth may be changed. For example, the subcarrier spacing of the bandwidth may be changed to allow a different service. A subset of a total cell bandwidth of a cell may be called a bandwidth part (BWP). The BA may be performed when the BS/network configures the BWP to the UE and the BS/network informs the UE of the BWP currently in an active state among the configured BWPs.

For example, the BWP may be at least any one of an active BWP, an initial BWP, and/or a default BWP. For example, the UE may not monitor downlink radio link quality in a DL BWP other than an active DL BWP on a primary cell (PCell). For example, the UE may not receive PDCCH, PDSCH, or CSI-RS (excluding RRM) outside the active DL BWP. For example, the UE may not trigger a channel state information (CSI) report for the inactive DL BWP. For example, the UE may not transmit PUCCH or PUSCH outside an active UL BWP. For example, in a downlink case, the initial BWP may be given as a consecutive RB set for an RMSI CORESET (configured by PBCH). For example, in an uplink case, the initial BWP may be given by SIB for a random access procedure. For example, the default BWP may be configured by a higher layer. For example, an initial value of the default BWP may be an initial DL BWP. For energy saving, if the UE fails to detect DCI during a specific period, the UE may switch the active BWP of the UE to the default BWP.

Meanwhile, the BWP may be defined for SL. The same SL BWP may be used in transmission and reception. For example, a transmitting UE may transmit an SL channel or an SL signal on a specific BWP, and a receiving UE may receive the SL channel or the SL signal on the specific BWP. In a licensed carrier, the SL BWP may be defined separately from a Uu BWP, and the SL BWP may have configuration signaling separate from the Uu BWP. For example, the UE may receive a configuration for the SL BWP from the BS/network. The SL BWP may be (pre-)configured in a carrier with respect to an out-of-coverage NR V2X UE and an RRC_IDLE UE. For the UE in the RRC_CONNECTED mode, at least one SL BWP may be activated in the carrier.

FIG. 7 shows an example of a BWP, in accordance with an embodiment of the present disclosure. The embodiment of FIG. 7 may be combined with various embodiments of the present disclosure. It is assumed in the embodiment of FIG. 7 that the number of BWPs is 3.

Referring to FIG. 7, a common resource block (CRB) may be a carrier resource block numbered from one end of a carrier band to the other end thereof. In addition, the PRB may be a resource block numbered within each BWP. A point A may indicate a common reference point for a resource block grid.

The BWP may be configured by a point A, an offset NstartBWP from the point A, and a bandwidth NsizeBWP. For example, the point A may be an external reference point of a PRB of a carrier in which a subcarrier 0 of all numerologies (e.g., all numerologies supported by a network on that carrier) is aligned. For example, the offset may be a PRB interval between a lowest subcarrier and the point A in a given numerology. For example, the bandwidth may be the number of PRBs in the given numerology.

Hereinafter, V2X or SL communication will be described.

FIG. 8A and FIG. 8B show a radio protocol architecture for a SL communication, in accordance with an embodiment of the present disclosure. The embodiment of FIG. 8A and FIG. 8B may be combined with various embodiments of the present disclosure. More specifically, FIG. 8A shows a user plane protocol stack, and FIG. 8B shows a control plane protocol stack.

Hereinafter, a sidelink synchronization signal (SLSS) and synchronization information will be described.

The SLSS may include a primary sidelink synchronization signal (PSSS) and a secondary sidelink synchronization signal (SSSS), as an SL-specific sequence. The PSSS may be referred to as a sidelink primary synchronization signal (S-PSS), and the SSSS may be referred to as a sidelink secondary synchronization signal (S-SSS). For example, length-127 M-sequences may be used for the S-PSS, and length-127 gold sequences may be used for the S-SSS. For example, a UE may use the S-PSS for initial signal detection and for synchronization acquisition. For example, the UE may use the S-PSS and the S-SSS for acquisition of detailed synchronization and for detection of a synchronization signal ID.

A physical sidelink broadcast channel (PSBCH) may be a (broadcast) channel for transmitting default (system) information which must be first known by the UE before SL signal transmission/reception. For example, the default information may be information related to SLSS, a duplex mode (DM), a time division duplex (TDD) uplink/downlink (UL/DL) configuration, information related to a resource pool, a type of an application related to the SLSS, a subframe offset, broadcast information, or the like. For example, for evaluation of PSBCH performance, in NR V2X, a payload size of the PSBCH may be 56 bits including 24-bit CRC.

The S-PSS, the S-SSS, and the PSBCH may be included in a block format (e.g., SL synchronization signal (SS)/PSBCH block, hereinafter, sidelink-synchronization signal block (S-SSB)) supporting periodical transmission. The S-SSB may have the same numerology (i.e., SCS and CP length) as a physical sidelink control channel (PSCCH)/physical sidelink shared channel (PSSCH) in a carrier, and a transmission bandwidth may exist within a (pre-)configured sidelink (SL) BWP. For example, the S-SSB may have a bandwidth of 11 resource blocks (RBs). For example, the PSBCH may exist across 11 RBs. In addition, a frequency position of the S-SSB may be (pre-)configured. Accordingly, the UE does not have to perform hypothesis detection at frequency to discover the S-SSB in the carrier.

FIG. 9 shows a UE performing V2X or SL communication, in accordance with an embodiment of the present disclosure. The embodiment of FIG. 9 may be combined with various embodiments of the present disclosure.

Referring to FIG. 9, in V2X or SL communication, the term ‘UE’ may generally imply a UE of a user. However, if a network equipment such as a BS transmits/receives a signal according to a communication scheme between UEs, the BS may also be regarded as a sort of the UE. For example, a UE 1 may be a first apparatus 100, and a UE 2 may be a second apparatus 200.

For example, the UE 1 may select a resource unit corresponding to a specific resource in a resource pool which implies a set of series of resources. In addition, the UE 1 may transmit an SL signal by using the resource unit. For example, a resource pool in which the UE 1 is capable of transmitting a signal may be configured to the UE 2 which is a receiving UE, and the signal of the UE 1 may be detected in the resource pool.

Herein, if the UE 1 is within a connectivity range of the BS, the BS may inform the UE 1 of the resource pool. Otherwise, if the UE 1 is out of the connectivity range of the BS, another UE may inform the UE 1 of the resource pool, or the UE 1 may use a pre-configured resource pool.

In general, the resource pool may be configured in unit of a plurality of resources, and each UE may select a unit of one or a plurality of resources to use it in SL signal transmission thereof.

Hereinafter, resource allocation in SL will be described.

FIG. 10A and FIG. 10B show a procedure of performing V2X or SL communication by a UE based on a transmission mode, in accordance with an embodiment of the present disclosure. The embodiment of FIG. 10A and FIG. 10B may be combined with various embodiments of the present disclosure. In various embodiments of the present disclosure, the transmission mode may be called a mode or a resource allocation mode. Hereinafter, for convenience of explanation, in LTE, the transmission mode may be called an LTE transmission mode. In NR, the transmission mode may be called an NR resource allocation mode.

For example, FIG. 10A shows a UE operation related to an LTE transmission mode 1 or an LTE transmission mode 3. Alternatively, for example, FIG. 10A shows a UE operation related to an NR resource allocation mode 1. For example, the LTE transmission mode 1 may be applied to general SL communication, and the LTE transmission mode 3 may be applied to V2X communication.

For example, FIG. 10B shows a UE operation related to an LTE transmission mode 2 or an LTE transmission mode 4. Alternatively, for example, FIG. 10B shows a UE operation related to an NR resource allocation mode 2.

Referring to FIG. 10A, in the LTE transmission mode 1, the LTE transmission mode 3, or the NR resource allocation mode 1, a BS may schedule an SL resource to be used by the UE for SL transmission. For example, the BS may perform resource scheduling to a UE 1 through a PDCCH (more specifically, downlink control information (DCI)), and the UE 1 may perform V2X or SL communication with respect to a UE 2 according to the resource scheduling. For example, the UE 1 may transmit a sidelink control information (SCI) to the UE 2 through a physical sidelink control channel (PSCCH), and thereafter transmit data based on the SCI to the UE 2 through a physical sidelink shared channel (PSSCH).

Referring to FIG. 10B, in the LTE transmission mode 2, the LTE transmission mode 4, or the NR resource allocation mode 2, the UE may determine an SL transmission resource within an SL resource configured by a BS/network or a pre-configured SL resource. For example, the configured SL resource or the pre-configured SL resource may be a resource pool. For example, the UE may autonomously select or schedule a resource for SL transmission. For example, the UE may perform SL communication by autonomously selecting a resource within a configured resource pool. For example, the UE may autonomously select a resource within a selective window by performing a sensing and resource (re)selection procedure. For example, the sensing may be performed in unit of subchannels. In addition, the UE 1 which has autonomously selected the resource within the resource pool may transmit the SCI to the UE 2 through a PSCCH, and thereafter may transmit data based on the SCI to the UE 2 through a PSSCH.

FIG. 11A through FIG. 11C show three cast types, in accordance with an embodiment of the present disclosure. The embodiment of FIG. 11A through FIG. 11C may be combined with various embodiments of the present disclosure. Specifically, FIG. 11A shows broadcast-type SL communication, FIG. 11B shows unicast type-SL communication, and FIG. 11C shows groupcast-type SL communication. In case of the unicast-type SL communication, a UE may perform one-to-one communication with respect to another UE. In case of the groupcast-type SL transmission, the UE may perform SL communication with respect to one or more UEs in a group to which the UE belongs. In various embodiments of the present disclosure, SL groupcast communication may be replaced with SL multicast communication, SL one-to-many communication, or the like.

Meanwhile, in sidelink communication, a UE may need to effectively select a resource for sidelink transmission. Hereinafter, a method in which a UE effectively selects a resource for sidelink transmission and an apparatus supporting the method will be described according to various embodiments of the present disclosure. In various embodiments of the present disclosure, the sidelink communication may include V2X communication.

At least one scheme proposed according to various embodiments of the present disclosure may be applied to at least any one of unicast communication, groupcast communication, and/or broadcast communication.

At least one method proposed according to various embodiment of the present embodiment may apply not only to sidelink communication or V2X communication based on a PC5 interface or an SL interface (e.g., PSCCH, PSSCH, PSBCH, PSSS/SSSS, etc.) or V2X communication but also to sidelink communication or V2X communication based on a Uu interface (e.g., PUSCH, PDSCH, PDCCH, PUCCH, etc.).

In various embodiments of the present disclosure, a receiving operation of a UE may include a decoding operation and/or receiving operation of a sidelink channel and/or sidelink signal (e.g., PSCCH, PSSCH, PSFCH, PSBCH, PSSS/SSSS, etc.). The receiving operation of the UE may include a decoding operation and/or receiving operation of a WAN DL channel and/or a WAN DL signal (e.g., PDCCH, PDSCH, PSS/SSS, etc.). The receiving operation of the UE may include a sensing operation and/or a CBR measurement operation. In various embodiments of the present disclosure, the sensing operation of the UE may include a PSSCH-RSRP measurement operation based on a PSSCH DM-RS sequence, a PSSCH-RSRP measurement operation based on a PSSCH DM-RS sequence scheduled by a PSCCH successfully decoded by the UE, a sidelink RSSU (S-RSSI) measurement operation, and an S-RSSI measurement operation based on a V2X resource pool related subchannel. In various embodiments of the disclosure, a transmitting operation of the UE may include a transmitting operation of a sidelink channel and/or a sidelink signal (e.g., PSCCH, PSSCH, PSFCH, PSBCH, PSSS/SSSS. etc.). The transmitting operation of the UE may include a transmitting operation of a WAN UL channel and/or a WAN UL signal (e.g., PUSCH, PUCCH, SRS, etc.). In various embodiments of the present disclosure, a synchronization signal may include SLSS and/or PSBCH.

In various embodiments of the present disclosure, a configuration may include signaling, signaling from a network, a configuration from the network, and/or a pre-configuration from the network. In various embodiments of the present disclosure, a definition may include signaling, signaling from a network, a configuration form the network, and/or a pre-configuration from the network. In various embodiment of the present disclosure, a designation may include signaling, signaling from a network, a configuration from the network, and/or a pre-configuration from the network.

In various embodiments of the present disclosure, a ProSe per packet priority (PPPP) may be replaced with a ProSe per packet reliability (PPPR), and the PPPR may be replaced with the PPPP. For example, it may mean that the smaller the PPPP value, the higher the priority, and that the greater the PPPP value, the lower the priority. For example, it may mean that the smaller the PPPR value, the higher the reliability, and that the greater the PPPR value, the lower the reliability. For example, a PPPP value related to a service, packet, or message related to a high priority may be smaller than a PPPP value related to a service, packet, or message related to a low priority. For example, a PPPR value related to a service, packet, or message related to a high reliability may be smaller than a PPPR value related to a service, packet, or message related to a low reliability

In various embodiments of the present disclosure, a session may include at least any one of a unicast session (e.g., unicast session for sidelink), a groupcast/multicast session (e.g., groupcast/multicast session for sidelink), and/or a broadcast session (e.g., broadcast session for sidelink).

In various embodiments of the present disclosure, a carrier may be interpreted as at least any one of a BWP and/or a resource pool. For example, the carrier may include at least any one of the BWP and/or the resource pool. For example, the carrier may include one or more BWPs. For example, the BWP may include one or more resource pools.

In the present disclosure, for example, definition, concept, content and/or function represented by the term “transmitting terminal” may be same or similar with definition, concept, content and/or function represented by a TX UE, a transmitting apparatus, a transmitting UE, a transmission UE, a transmission terminal, a first apparatus, a first terminal, an apparatus, etc.

In the present disclosure, for example, definition, concept, content and/or function represented by the term “receiving terminal” may be same or similar with definition, concept, content and/or function represented by a RX UE, a receiving apparatus, a receiving UE, a reception UE, a reception terminal, a second apparatus, a second terminal, an apparatus, etc.

In the present disclosure, the wording “TX UE” may be interpreted as UE performing data transmission (for example, PSCCH/PSSCH) (to the (target) RX UE), and/or UE performing SL CSI-RS (and/or SL CSI report request indicator) transmission (to the (target) RX UE), and/or

UE performing transmission of RS (for example, PSSCH DMRS) (and/or SL (L1) RSRP report request indicator) which will be used for SL (L1) RSRP measurement (to the (target) RX UE), and/or UE transmitting (control) channel and/or RS (on the (control) channel) (for example, DM-RS, CSI-RS) that will be used for SL radio link monitoring (RLM) (and/or SL radio link failure (RLF)) operation (to the (target) RX UE).

In the present disclosure, the transmitting terminal may be a terminal that transmits data (eg, PSCCH and/or PSSCH) to the (target) receiving terminal. Alternatively, the transmitting terminal may be a terminal that performs transmission of sidelink channel state information reference signal (SL CSI-RS) for measuring sidelink channel state information and/or SL CSI report request indicator (or sidelink channel state information report request information) to the (target) receiving terminal. Alternatively, the transmitting terminal may be a terminal that performs transmission of a reference signal for sidelink reference signal received power (RSRP) measurement and/or a sidelink RSRP report request indicator (or sidelink RSRP report request information) to the (target) receiving terminal. In this case, as an example, the sidelink RSRP may be an RSRP measurement value calculated using filtering of a layer-1 (L1) layer. As an example, the reference signal for measuring the sidelink RSRP may be a predefined reference signal. As an example, the reference signal for RSRP measurement may be a PSSCH Demodulation Reference Signal (DMRS), a DMRS for PSSCH, or a DMRS associated with PSSCH. Alternatively, the transmitting terminal may be a terminal that transmits a channel for sidelink radio link monitoring (SL RLM) and/or sidelink radio link failure (SL RLF) operation of the receiving terminal. Alternatively, the transmitting terminal may be a terminal that transmits a reference signal (eg, DMRS or CSI-RS) on a channel for SL RLM and/or SL RLF operation of the (target) receiving terminal. In this case, as an example, a channel for SL RLM and/or SL RLF operation of the receiving terminal may be PSCCH or PSSCH.

In the present disclosure, the wording “RX UE” may be interpreted as UE transmitting SL HARQ feedback (to the TX UE) according to whether the decoding of the data received from the TX UE is successful (and/or whether the detection/decoding of the PSCCH (related to PSSCH scheduling) transmitted by the TX UE is successful), and/or UE performing SL CSI transmission (to the TX UE) based on SL CSI-RS (and/or SL CSI report request indicator) received from the TX UE and/or UE transmitting SL (L1) RSRP measurement value (to the TX UE) based on (pre-defined) RS (and/or SL (L1) RSRP report request indicator) received from the TX UE, and/or UE performing data transmission of itself (for the TX UE), and/or UE performing RLM (and/or RLF) operation based on (pre-configured) (control) channel and/or RS (on the (control) channel) received from the TX UE.

In the present disclosure, the receiving terminal may be a terminal that transmits SL HARQ feedback information (to the transmitting terminal) according to whether decoding of data received from the transmitting terminal is successful and/or whether detection/decoding of PSCCH (related to scheduling of PSSCH) transmitted from the transmitting terminal is successful. Alternatively, the receiving terminal may be a terminal that performs SL CSI transmission (to the transmitting terminal) based on the SL CSI-RS and/or SL CSI report request indicator (or SL CSI report request information) received from the transmitting terminal. Alternatively, the receiving terminal may be a terminal that transmits sidelink RSRP measurement value (to the transmitting terminal) based on the (pre-defined) reference signal and/or the sidelink RSRP report request indicator (or sidelink RSRP report request information) received from the transmitting terminal. In this case, as an example, the sidelink RSRP may be an RSRP measurement value calculated using filtering of a layer-1 (L1) layer. Alternatively, the receiving terminal may be a terminal that transmits data of the receiving terminal itself (to the transmitting terminal). As an example, the receiving terminal may be a terminal that performs SL RLM and/or SL RLF operations based on a (pre-configured) channel received from a transmitting terminal and/or a reference signal received on the channel. In this case, for example, the channel may be a control channel.

As an example, in the present disclosure, the “configuration (or definition)” wording may be interpreted as being (pre) configured (through pre-defined signaling (eg, SIB, MAC, RRC)) from a base station (or network). In addition, in the present disclosure, the “RLF” wording may be extended and interpreted as at least one of OUT-OF-SYNCH (OOS) and IN-SYNCH (IS). Additionally, in the present disclosure, “RB” wording may be extensively interpreted as subcarrier.

In the present disclosure, terms expressed as “configuration” or “definition” may be interpreted as being pre-configured or configured from a base station or network (through pre-defined signaling (for example, SIB, MAC signaling, RRC signaling)). For example, “A may be configured” may include “a base station or network setting, defining and/or notifying A to the terminal (in advance)”. Alternatively, terms expressed as “configuration” or “definition” may be interpreted as being configured or defined in advance by the system. For example, “A may be configured” may include “A is configured/defined in advance by system”.

In the present specification, the SL RLF may be determined based on at least one of OUT-OF-SYNCH (OOS or Out-of-Sync.) or IN-SYNCH (IS or In-Sync.).

In the present specification, a resource block (RB) may be replaced by a subcarrier.

As an example, in the present disclosure, for convenience of description, the (physical) channel used when the RX UE transmits at least one of the following information to the TX UE is referred to as “physical sidelink feedback channel (PSFCH)”. As an example, when the RX UE transmits SL HARQ feedback information for the PSSCH (and/or PSCCH) received from the TX UE, the following (some) schemes (OPTION: OPTION A and/or OPTION B) may be considered. Here, as an example, the (some) scheme may be limitedly applied only when the RX UE successfully decodes/detects the PSCCH for scheduling the PSSCH.

OPTION A: transmits NACK information only when decoding/reception for the PSSCH fails

OPTION B: transmits ACK information when decoding/reception for the PSSCH is successful, and transmits NACK information when it fails

For example, in the case of GROUPCAST, for (one) PSSCH (and/or PSCCH) transmitted by the TX UE, a plurality of RX UEs should transmit SL HARQ feedback. In other words, as an example, a plurality of PSFCH resources linked/mapped with one PSSCH (and/or PSCCH) transmission (resource) need to be effectively defined/operated.

In the present disclosure, the receiving terminal may transmit (to the transmitting terminal) at least one of sidelink HARQ feedback, SL CSI or sidelink RSRP. In this specification, the physical channel used when the receiving terminal transmits at least one of sidelink HARQ feedback, sidelink CSI, or sidelink RSRP (to the transmitting terminal) may be referred to as a physical sidelink feedback channel (PSFCH) or a sidelink feedback channel In this case, as an example, the sidelink RSRP may be an RSRP measurement value calculated using filtering of a layer-1 (L1) layer.

In the present disclosure, when the receiving terminal transmits sidelink HARQ feedback information for the PSSCH and/or PSCCH transmitted from the transmitting terminal, the following (some) methods may be applied. Alternatively, the following (some) schemes may be limitedly applied only when the receiving terminal successfully detects and/or decodes the PSSCH (or PSCCH) for scheduling the PSSCH.

Method A: NACK (Negative-acknowledgement) information is transmitted only when the receiving terminal fails to decode and/or receive the PSSCH transmitted from the transmitting terminal.

Method B: When the receiving terminal succeeds in decoding and receiving the PSSCH transmitted from the transmitting terminal, it transmits ACK (Acknowledgement) information, and when it fails, transmits NACK information.

Meanwhile, sidelink groupcast transmission may be supported in the next communication system. Sidelink groupcast transmission is used when a specific transmitting terminal transmits (control information/data to) multiple receiving terminals. In this case, the sidelink groupcase transmission may be supported in an in-coverage scenario, an out-of coverage scenario and a partial-coverage scenario. Here, the sidelink groupcase transmission may be replaced by a sidelink multicast transmission, a sidelink one-to-may transmission, or the like.

Meanwhile, when the sidelink groupcast transmission is supported, the transmitting terminal may transmit PSSCH and/or PSCCH to multiple receiving terminals. In this case, each of the multiple receiving terminals may transmit HARQ feedback information for (one) PSSCH and/or PSCCH received from the transmitting terminal. For this, it is necessary to effectively define/operate multiple physical sidelink feedback channel (PSFCH) resources (for transmission of each of multiple receiving terminals) having linkage or being mapped with one PSCCH transmission (or PSSCH resource) and/or PSCCH transmission (or PSCCH resource).

As an example, the following examples (for example, [proposed method #1] and/or [proposed method #2]) propose a method for solving the above issue.

Thus, at the following, according to an embodiment of the present specification, by the needs such as above, a method of configuring a resource for a transmission of HARQ feed back of a terminal and an apparatus supporting the same, when the sidelink groupcase transmission is supported, will be explained.

[Proposed method #1] As an example, in the HARQ feedback resource set (HRFEED_RSCSET) related/linked with (one) PSSCH (and/or PSCCH) transmission (resource), based on the following (some) parameters (through a predefined function), a plurality of PSFCH resources may be defined/distinguished. As an example, according to parameters such as the HRFEED_RSCSET-related resource size (eg, the number of RBs), individual PSFCH resources in the HRFEED_RSCSET are appropriately defined, so that mutual interference may be reduced. Here, as a specific example, when the number of RX UEs receiving (one) PSSCH (and/or PSCCH) transmitted from the TX UE is 4, and the size of HRFEED_RSCSET resource size is 1RB, PSFCH resources of 4 sequences/codes for which CDM has been performed are defined (in 1RB). On the other hand, when the HRFEED_RSCSET resource size is 2 RBs, PSFCH resources of 2 sequences/codes for which CDM has been performed may be defined for each RB. In addition, as an example, HRFEED_RSCSET related/linked with (one) PSSCH (and/or PSCCH) transmission (resource) may be determined based on (pre-defined) function having below (some) parameters as input variables. As an additional example, the proposed method may be limitedly applied to the SL HARQ feedback method (and/or pre-configured cast type (eg, groupcast) and/or service type/priority, and/or SL pathloss-based PSFCH OLPC is not configured) of (above explained) OPTION A.

PSSCH (and/or PSCCH) Transmission Related Factors

Example) PSSCH (and/or PSCCH) related transmission resource parameter (e.g., lowest (or highest) RB (and/or control channel index (CCE)) index, number of RBs (and/or CCE), start (or last) symbol index, number of symbols, slot index (and/or number), etc.)

Example) PSSCH (and/or PSCCH) related DM-RS parameters (e.g., sequence generation seed (and/or ID) value, cyclic shift (and/or OCC) index, etc.)

Example) SLSS (SIDELINK SYNCH. SEQUENCE) ID

Example) (TX UE) (L1 or L2) SOURCE ID (and/or (RX UE) (L1 or L2) DESTINATION ID)

Example) PSCCH (and/or PSSCH) related (pre-configured some (or all)) CRC bit

Example) PSSCH (and/or PSCCH) related antenna port index (and/or RANK information)

Example) PSSCH (and/or PSCCH) related REDUNDANCY VERSION (RV) (and/or transmission order/number (eg, when transmitting (repeated) one TB through N SLOTs, transmission sequence number/count)

HRFEED_RSCSET Related Factors

Example) HRFEED_RSCSET related RB (and/or symbol) number and/or lowest (or highest) RB index (and/or starting (or last) symbol index) and/or SLOT index (and/or number)

Example) (L1 or L2) SOURCE ID of a terminal performing PSFCH transmission (and/or (L1 or L2) DESTINATION ID of a terminal receiving it)

Example) HRFEED_RSCSET related antenna port index

[proposed method #2] For example, the RX UE may be controlled to, when the RX UE transmits SL HARQ feedback to the TX UE that has transmitted PSSCH (and/or PSCCH), (A) transmit by using (time/frequency) synchronization derived from SYNCH. SOURCE REFERENCE related to a transmission operation of itself, or (B) transmit by using (time/frequency) synchronization derived from SYNCH. SOURCE REFERENCE used for the reception operation of PSSCH (and/or PSCCH) of TX UE (or (time/frequency) synchronization derived from SYNCH. SOURCE REFERENCE related to the reception operation of itself). Here, as an example, the SL HARQ feedback resource transmitted by the RX UE (or the SL HARQ feedback resource received by the TX UE) may be configured on its own reception (or transmission) resource pool.

At the following FIG. 12 and FIG. 13, in relation to the above-described [Proposed method #1], at least one HARQ feedback of the N receiving terminals for PSSCH transmission of the transmitting terminal according to some embodiments is reviewed.

Meanwhile, in the present disclosure, “PSFCH resource” may represent a resource for transmitting HARQ feedback. In one example, the PSFCH resource may represent a resource configured based on a time resource and a frequency resource. In another example, the PSFCH resource may be represented by a PSFCH PRB set. For example, the PSFCH PRB set may be composed of A RBs, where the A denotes a natural number.

FIG. 12 shows at least one HARQ feedback of N receiving terminals for PSSCH transmission of a transmitting terminal according to an embodiment of the present disclosure, and FIG. 13 shows at least one HARQ feedback of N receiving terminals for PSSCH transmission of a transmitting terminal according to another embodiment of the present disclosure.

Referring to FIG. 12, a transmitting terminal 1201 according to an embodiment may transmit PSSCH (and/or PSCCH) to N receiving terminals 1204 (N is a natural number) including receiving terminal 1 1202 through receiving terminal N 1203. N receiving terminals 1204 according to an embodiment may transmit at least one HARQ feedback for the PSSCH to the transmitting terminal 1201 based on M PSFCH resources 1210 (M is a natural number) including PSFCH resource 1 (1212), PSFCH resource 2 (1214), PSFCH resource 3 (1216), . . . , PSFCH resource M 1218.

In an embodiment, based on that N is less than or equal to M, the at least one HARQ feedback may be received (or configured) on N PSFCH resources of the M PSFCH resources 1210, respectively. In one example, referring to FIG. 12, based on that N is 2 and N=2 is smaller than M, two HARQ feedbacks may be received (or configured) on two PSFCH resources 1212 and 1214 of the M PSFCH resources 1210, respectively.

In one example, time resource of each of the N PSFCH resources (in the example of FIG. 12, two PSFCH resources 1212 and 1214) overlaps with each other, and each of the N PSFCH resources may be adjacent to one PSFCH resource or two PSFCH resources among the M PSFCH resources 1210 on frequency resource.

In an example, at least one cyclic shift (CS) value for the at least one HARQ feedback (in the example of FIG. 12, two HARQ feedbacks) may be the same.

In another embodiment, based on that the number L of the at least one HARQ feedback (L is a natural number) is less than or equal to the M, the number L of at least one HARQ feedback may be received (or configured) on L PSFCH resources of the M PSFCH resources 1210, respectively. In one example, referring to FIG. 12, based on that N is greater than 2 and L=2 is less than M, two HARQ feedbacks may be received (or configured) on 2 PSFCH resources 1212 and 1214 among the M PSFCH resources 1210, respectively.

In one example, time resource of each of the L PSFCH resources (in the example of FIG. 12, two PSFCH resources 1212 and 1214) overlaps with each other, and each of the N PSFCH resources may be adjacent to one PSFCH resource or two PSFCH resources among the M PSFCH resources 1210 on frequency resource.

In one example, at least one cyclic shift (CS) value for the L HARQ feedbacks (in the example of FIG. 12, two HARQ feedbacks) may be the same.

Referring to FIG. 13, a transmitting terminal 1301 according to an embodiment may transmit PSSCH (and/or PSCCH) to N receiving terminals (1304) (N is a natural number) including a receiving terminal 1 1302 through a receiving terminal N 1303. N receiving terminals 1304 according to an embodiment may transmit at least one HARQ feedback for the PSSCH to the transmitting terminal 1301 based on the M PSFCH resources 1310 (M is a natural number) including PSFCH resource 1 (1312), PSFCH resource 2 (1314), PSFCH resource 3 (1316), . . . , PSFCH resource M 1318.

In an embodiment, based on that N is greater than M, at least one PSFCH resource based on different cyclic shift (CS) values may be configured on the M PSFCH resources 1310. In this case, the M PSFCH resources 1310 may be configured based on time resources and frequency resources. For example, the M PSFCH resources 1310 may be configured without considering code resources. N and M are natural numbers (or positive integers). In one example, referring to FIG. 13, based on that N is greater than M, P HARQ feedbacks (here, P may be equal to N or may be smaller than N) may be received (or configured) on M PSFCH resources 1310. At this time, each of at least one PSFCH resource (two PSFCH resources 1312 and 1314 in the example of FIG. 13) may be related to a plurality of HARQ feedbacks based on different CS values.

In one example, referring to FIG. 13, each of at least one PSFCH resource (in the example of FIG. 13, two PSFCH resources 1312 and 1314) among M PSFCH resources 1310 may be related to Q HARQ feedbacks based on different CS values. And, each of the remaining PSFCH resources 1316, 1318, etc. among the M PSFCH resources 1310 may be related to Q-1 HARQ feedback based on different CS values. For example, referring to FIG. 13, each of the two PSFCH resources 1312 and 1314 of the M PSFCH resources 1310 may be related to two HARQ feedbacks based on different CS values. And, each of the remaining PSFCH resources 1316, 1318, etc. among the M PSFCH resources 1310 may be related to one HARQ feedback based on different CS values.

In an example, the at least one PSFCH resource may be at least one PSFCH resource related to the lowest frequency among the M PSFCH resources 1310.

Hereinafter, some embodiments applicable to FIG. 12 and/or FIG. 13 will be described.

According to an embodiment of the present disclosure, in a resource set (HRFEED_RSCSET) for HARQ feedback information transmission of multiple receiving terminals having linkage, being related or being mapped with (one) PSSCH transmission (or PSSCH transmission resource) and/or PSCCH transmission (or PSCCH transmission resource), individual PSFCH resources of the multiple receiving terminals may be defined or may be distinguished from each other based on at least one parameter of below table 5 (by using pre-defined function). For example, according to parameters such as the size of HRFEED_RSCSET, individual PSFCH resources of the multiple receiving terminals in the HRFEED_RSCSET are appropriately defined to reduce mutual interference between individual HARQ feedback information transmissions of the multiple receiving terminals. In this case, the size of the HRFEED_RSCSET may be expressed as the number of RBs (eg, N RB. N is a natural number). Specifically, when the number of receiving terminals receiving (one) PSSCH and/or PSCCH transmitted from the transmitting terminal is 4, and the size of HRFEED_RSCSET is 1 RB, 4 sequences and/or codes are applied in HRFEED_RSCSET of 1 RB, and therefore, four PSFCH resources for which code division multiplexing (CDM) has been performed may be defined. Meanwhile, when the number of receiving terminals that receive (one) PSSCH and/or PSCCH transmitted from the transmitting terminal is 4 and the size of HRFEED_RSCSET is 2 RBs, 2 sequences and/or codes are applied to each RB, and therefore, two PSFCH resources for which CDM has been performed may be defined for the each RB.

According to an embodiment of the present disclosure, HRFEED_RSCSET that having linkage, being related or being mapped with (one) PSSCH transmission (or PSSCH transmission resource) and/or PSCCH transmission (or PSCCH transmission resource) may be determined based on (pre-defined) function including at least one of parameters of below table 5 as input variables.

TABLE 5 classify/cause example of parameter regarding PSSCH and/or a lowest RB index, a highest RB index, a lowest control channel PSCCH transmission element (CCE) index, a highest CCE index, the number of RB(s), the number of CCE(s), starting symbol index, last symbol index, the number of symbol(s), slot index and/or the number of slot(s), etc DMRS parameter related to PSSCH and/or PSCCH (for example, sequence generation seed, sequence generation ID, cyclic shift index and/or orthogonal cover code (OCC) index, etx) sidelink synchronization signal (SLSS) ID transmitting terminal (L1 or L2) source ID and/or receiving terminal (L1 or L2) destination ID pre-configured some CRC bits or all CRC bits antenna port index and/or rank (or layer) information RV (Redundancy version) and/or transmission order/number (for example, transmission order/number in case of transmitting one transport block (TB) through N slots regarding the number of RB(s), the number of symbol(s), a lowest RB index, HRFEED_RSCSET a highest RB index, starting symbol index, last symbol index, slot index and/or the number of slot(s) (L1 or L2) source ID of PSFCH transmission terminal and/or (L1 or L2) destination ID of PSFCH reception terminal antenna port index

Meanwhile, the embodiments may be limitedly applied to the case of transmitting the sidelink HARQ feedback of the scheme A and/or the scheme B. And/or, the above embodiments may be limitedly applied to the case of communication using a pre-set cast method (eg, group cast). And/or, the embodiments may be limitedly applied according to a specific service type and/or a specific service priority. And/or, it may be limitedly applied when PSFCH open-loop power control (OLPC) based on Sidelink Pathloss is not configured.

Hereinafter, in FIG. 14, some examples in which PSFCH resources for HARQ feedback are configured are reviewed in relation to the above-described [proposed method #2].

FIG. 14 is a diagram for describing an example in which a PSFCH resource for HARQ feedback is configured.

According to an embodiment of the present disclosure, when a receiving terminal transmits sidelink HARQ feedback information to a transmitting terminal that has transmitted PSSCH and/or PSCCH, the receiving terminal may obtain time/frequency synchronization derived from synchronization source reference related to the transmission of the receiving terminal itself, and may perform sidelink HARQ feedback information transmission. Alternatively, when the receiving terminal transmits sidelink HARQ feedback information to the transmitting terminal that has transmitted the PSSCH and/or PSCCH, the receiving terminal may obtain time/frequency synchronization derived from synchronization source reference used for PSSCH and/or PSCCH reception operation of the transmitting terminal, and may perform sidelink HARQ feedback information transmission. Meanwhile, the sidelink HARQ feedback information transmission resource of the receiving terminal may be configured on the receiving terminal's own Rx Resource pool. Alternatively, the HARQ feedback information reception resource of the transmitting terminal may be configured on its own transmission resource pool (Tx Resource pool).

Referring to FIG. 14, TX resource pools/RX resource pools 1410, 1430, and 1450 and RX resource pools 1420 and 1440 of the receiving terminal are shown based on the receiving terminal. The receiving terminal according to an embodiment may transmit HARQ feedback for the PSSCH and/or PSCCH on the TX resource pool/RX resource pool 1410, 1430, 1450 or RX resource pool 1420, 1440 to the transmitting terminal after receiving PSCCH and/or PSCCH from the transmitting terminal on the TX resource pool/RX resource pool 1410, 1430, 1450. That is, the PSFCH resource for transmitting the HARQ feedback for the PSSCH and/or PSCCH may be configured on the TX resource pool/RX resource pool 1410, 1430, 1450 or the RX resource pool 1420, 1440 of the receiving terminal.

In one example, the receiving terminal may transmit HARQ feedback for the PSSCH and/or PSCCH on the RX resource pool 1420 or RX resource pool 1440 rather than the TX resource pool/RX resource pool 1410, after receiving the PSSCH and/or PSCCH from the transmitting terminal on the TX resource pool/RX resource pool 1410. That is, PSFCH resources for transmitting HARQ feedback for the PSSCH and/or PSCCH may be configured on the RX resource pool 1420 or the RX resource pool 1440 of the receiving terminal.

FIG. 15 is a flowchart illustrating an operation of a first apparatus according to an embodiment of the present disclosure.

Operations disclosed in the flowchart of FIG. 15 may be performed in combination with various embodiments of the present disclosure. In one example, operations disclosed in the flowchart of FIG. 15 may be performed based on at least one of the devices illustrated in FIGS. 17 to 22. In an example, the first apparatus of FIG. 15 may correspond to the first wireless device 100 of FIG. 18 to be described later. In another example, the first apparatus of FIG. 15 may correspond to the second wireless device 200 of FIG. 18 to be described later.

In step S1510, a first apparatus according to an embodiment may transmit physical sidelink control channel (PSCCH) and physical sidelink shared channel (PSSCH) to N receiving apparatuses.

In step S1520, a first apparatus according to an embodiment may receive at least one hybrid automatic repeat request (HARQ) feedback for the PSSCH based on M physical sidelink feedback channel (PSFCH) physical resource block (PRB) sets.

In an embodiment, at least one PSFCH PRB set based on different CS values may be configured on the M PSFCH PRB sets based on that the N is bigger than the M. In this case, the N and the M may be positive integers.

In an embodiment, the number of the at least one PSFCH PRB set may be L, the at least one PSFCH PRB set may be L PSFCH PRB sets of lowest frequencies among the M PSFCH PRB sets, and the L may be a positive integer.

In an embodiment, each of the at least one HARQ feedback for the PSSCH may be prioritized to be configured in different PSFCH PRB sets within the M PSFCH PRB sets.

In an embodiment, based on that a part of the at least one HARQ feedback is configured for each of the M PSFCH PRB sets, a remaining part of the at least one HARQ feedback may be distinguished within the M PSFCH PRB sets based on a CS value different from CS values of the part of the at least one HARQ feedback.

In an embodiment, based on that the N is less than or equal to the M, the at least one HARQ feedback may be received on each of N PSFCH PRB sets among the M PSFCH PRB sets.

In an embodiment, each of the N PSFCH PRB sets overlaps time resources with each other, and is adjacent to one PSFCH PRB set or two PSFCH PRB sets among the N PSFCH PRB sets on a frequency resource.

In an embodiment, a part or all of the M PSFCH PRB sets may be configured or CS values related to the part or all of the M PSFCH PRB sets may be configured based on at least one of a minimum resource block (RB) index for the PSSCH, the number of RBs for the PSSCH, an RB index for the PSSCH, a source ID of the first apparatus, a slot index for the PSSCH or an index of a last PSSCH slot among a plurality of PSSCH slots related to the PSSCH linked to a slot in which a PSFCH resource related to the PSSCH is configured. In one example, the index of the last PSSCH slot among the plurality of PSSCH slots related to the PSSCH linked to the slot in which the PSFCH resource for the PSSCH is configured may represent a last slot index used for transmission of a transport block related to the PSSCH.

In an embodiment, based on at least one of a HARQ feedback scheme, a CS value, or a cast type, some or all of the M PSFCH PRB sets may be configured, or CS values for some or all of the M PSFCH PRB sets may be configured.

In an embodiment, the cast type may include a unicast type and a groupcast type, and based on whether the cast type is the unicast type or the groupcast type, the some or all of the M PSFCH PRB sets may be configured, or CS values for the some or all of the M PSFCH PRB sets may be configured.

In an embodiment, the HARQ feedback scheme may include a NACK only feedback scheme and an ACK/NACK feedback scheme, and, based on whether the HARQ feedback scheme is the NACK only feedback scheme or the ACK/NACK feedback scheme, the some or all of the M PSFCH PRB sets may be configured, or CS values for the some or all of the M PSFCH PRB sets may be configured.

In an embodiment, a PSFCH resource for HARQ feedback transmitted by one of the N receiving apparatuses to the first apparatus may be configured on a reception resource pool of the first apparatus or a reception resource pool of the one of the N receiving apparatuses.

In an embodiment, HARQ feedback transmitted by one of the N receiving apparatuses to the first apparatus may be transmitted based on synchronization derived from a synchronization source reference related to a transmission operation of the one of the N receiving apparatuses.

In an embodiment, HARQ feedback transmitted by one of the N receiving apparatuses to the first apparatus may be transmitted based on synchronization derived from a synchronization source reference used for the one of the N receiving apparatuses to receive the PSSCH or a synchronization source reference related to a reception resource pool in which a PSFCH resource for the one of the N receiving apparatuses is configured.

According to an embodiment of the present disclosure, a first apparatus for performing groupcast transmission may be provided. The first apparatus includes at least one memory storing instructions, at least one transceiver and at least one processor connecting the at least one memory and the at least one transceiver, wherein the at least one processor is configured to: control the transceiver to transmit physical sidelink control channel (PSCCH) and physical sidelink shared channel (PSSCH) to N receiving apparatuses, and control the transceiver to receive at least one hybrid automatic repeat request (HARQ) feedback for the PSSCH based on M physical sidelink feedback channel (PSFCH) physical resource block (PRB) sets, wherein, at least one PSFCH PRB set based on different CS values is configured on the M PSFCH PRB sets based on that the N is bigger than the M, and wherein the N and the M are positive integers.

According to an embodiment of the present disclosure, an apparatus (or chip(set)) controlling a first terminal may be provided. The apparatus includes at least one processor and at least one computer memory that is executably connected by the at least one processor and stores instructions, wherein, by the at least one processor executing the instructions, the first terminal: transmit physical sidelink control channel (PSCCH) and physical sidelink shared channel (PSSCH) to N receiving apparatuses, and receive at least one hybrid automatic repeat request (HARQ) feedback for the PSSCH based on M physical sidelink feedback channel (PSFCH) physical resource block (PRB) sets, wherein, at least one PSFCH PRB set based on different CS values is configured on the M PSFCH PRB sets based on that the N is bigger than the M, and wherein the N and the M are positive integers.

In an embodiment, the first terminal of the embodiment may represent the first apparatus described throughout the present disclosure. In an embodiment, the at least one processor, at least one memory, or the like in the apparatus for controlling the first terminal may be implemented as respective separate sub chips, or at least two or more components may be implemented through one sub chip.

According to an embodiment of the present disclosure, a non-transitory computer-readable storage medium having instructions stored thereon may be provided. Based on the instructions being executed by at least one processor: physical sidelink control channel (PSCCH) and physical sidelink shared channel (PSSCH) are transmitted to N receiving apparatuses by a first apparatus, and at least one hybrid automatic repeat request (HARQ) feedback for the PSSCH is received by the first apparatus based on M physical sidelink feedback channel (PSFCH) physical resource block (PRB) sets, wherein, at least one PSFCH PRB set based on different CS values is configured on the M PSFCH PRB sets based on that the N is bigger than the M, and wherein the N and the M may be positive integers.

FIG. 16 is a flowchart illustrating an operation of a second apparatus according to an embodiment of the present disclosure.

The operations disclosed in the flowchart of FIG. 16 may be performed in combination with various embodiments of the present disclosure. In one example, operations disclosed in the flowchart of FIG. 16 may be performed based on at least one of the devices illustrated in FIGS. 17 to 22. In one example, the second apparatus of FIG. 16 may correspond to the second wireless device 200 of FIG. 18 to be described later. In another example, the second apparatus of FIG. 16 may correspond to the first wireless device 100 of FIG. 18 to be described later.

In step S1610, a second apparatus according to an embodiment may receive PSCCH and PSSCH from a first apparatus.

In step S1620, a second apparatus according to an embodiment may transmit a first HARQ feedback for the PSSCH to the first apparatus on a first PSFCH PRB set.

In an embodiment, the PSSCH may be transmitted by the first apparatus to N receiving apparatuses including the second apparatus, at least one HARQ feedback for the PSSCH may be received by the first apparatus based on M PSFCH PRB sets, the at least one HARQ feedback may include the first HARQ feedback, at least one PSFCH PRB set based on different CS values may be configured on the M PSFCH PRB sets based on that the N is bigger than the M, the first PSFCH PRB set may be one PSFCH PRB set among the M PSFCH PRB sets, and the N and the M may be positive integers.

In an embodiment of the present disclosure, the number of the at least one PSFCH PRB set may be L, the at least one PSFCH PRB set may be L PSFCH PRB sets of lowest frequencies among the M PSFCH PRB sets, and the L may be a positive integer.

In an embodiment, each of the at least one HARQ feedback for the PSSCH may be prioritized to be configured in different PSFCH PRB sets within the M PSFCH PRB sets.

In an embodiment, based on that a part of the at least one HARQ feedback is configured for each of the M PSFCH PRB sets, a remaining part of the at least one HARQ feedback may be distinguished within the M PSFCH PRB sets based on a CS value different from CS values of the part of the at least one HARQ feedback.

In an embodiment, based on that the N is less than or equal to the M, the at least one HARQ feedback may be received on each of N PSFCH PRB sets among the M PSFCH PRB sets.

In an embodiment, each of the N PSFCH PRB sets overlaps time resources with each other, and is adjacent to one PSFCH PRB set or two PSFCH PRB sets among the N PSFCH PRB sets on a frequency resource.

In an embodiment, a part or all of the M PSFCH PRB sets may be configured or CS values related to the part or all of the M PSFCH PRB sets may be configured based on at least one of a minimum resource block (RB) index for the PSSCH, the number of RBs for the PSSCH, an RB index for the PSSCH, a source ID of the first apparatus, a slot index for the PSSCH or an index of a last PSSCH slot among a plurality of PSSCH slots related to the PSSCH linked to a slot in which a PSFCH resource related to the PSSCH is configured. In one example, the index of the last PSSCH slot among the plurality of PSSCH slots related to the PSSCH linked to the slot in which the PSFCH resource for the PSSCH is configured may represent a last slot index used for transmission of a transport block related to the PSSCH.

In an embodiment, based on at least one of a HARQ feedback scheme, a CS value, or a cast type, some or all of the M PSFCH PRB sets may be configured, or CS values for some or all of the M PSFCH PRB sets may be configured.

In an embodiment, the cast type may include a unicast type and a groupcast type, and based on whether the cast type is the unicast type or the groupcast type, the some or all of the M PSFCH PRB sets may be configured, or CS values for the some or all of the M PSFCH PRB sets may be configured.

In an embodiment, the HARQ feedback scheme may include a NACK only feedback scheme and an ACK/NACK feedback scheme, and, based on whether the HARQ feedback scheme is the NACK only feedback scheme or the ACK/NACK feedback scheme, the some or all of the M PSFCH PRB sets may be configured, or CS values for the some or all of the M PSFCH PRB sets may be configured.

In an embodiment, a PSFCH resource for HARQ feedback transmitted by one of the N receiving apparatuses to the first apparatus may be configured on a reception resource pool of the first apparatus or a reception resource pool of the one of the N receiving apparatuses.

In an embodiment, HARQ feedback transmitted by one of the N receiving apparatuses to the first apparatus may be transmitted based on synchronization derived from a synchronization source reference related to a transmission operation of the one of the N receiving apparatuses.

In an embodiment, HARQ feedback transmitted by one of the N receiving apparatuses to the first apparatus may be transmitted based on synchronization derived from a synchronization source reference used for the one of the N receiving apparatuses to receive the PSSCH or a synchronization source reference related to a reception resource pool in which a PSFCH resource for the one of the N receiving apparatuses is configured.

According to an embodiment of the present disclosure, a second apparatus for performing groupcast transmission may be provided. The second apparatus includes at least one memory storing instructions, at least one transceiver and at least one processor connecting the at least one memory and the at least one transceiver, wherein the at least one processor is configured to: control the at least one transceiver to receive PSCCH and PSSCH from a first apparatus, and control the at least one transceiver to transmit a first HARQ feedback for the PSSCH to the first apparatus on a first PSFCH PRB set, wherein the PSSCH is transmitted by the first apparatus to N receiving apparatuses including the second apparatus, wherein at least one HARQ feedback for the PSSCH is received by the first apparatus based on M PSFCH PRB sets, wherein the at least one HARQ feedback includes the first HARQ feedback, wherein, at least one PSFCH PRB set based on different CS values is configured on the M PSFCH PRB sets based on that the N is bigger than the M, wherein the first PSFCH PRB set is one PSFCH PRB set among the M PSFCH PRB sets, and wherein the N and the M are positive integers.

Various embodiments of the present disclosure may be independently implemented. Alternatively, the various embodiments of the present disclosure may be implemented by being combined or merged. For example, although the various embodiments of the present disclosure have been described based on the 3GPP LTE system for convenience of explanation, the various embodiments of the present disclosure may also be extendedly applied to another system other than the 3GPP LTE system. For example, the various embodiments of the present disclosure may also be used in an uplink or downlink case without being limited only to direct communication between terminals. In this case, a base station, a relay node, or the like may use the proposed method according to various embodiments of the present disclosure. For example, it may be defined that information on whether to apply the method according to various embodiments of the present disclosure is reported by the base station to the terminal or by a transmitting terminal to a receiving terminal through pre-defined signaling (e.g., physical layer signaling or higher layer signaling). For example, it may be defined that information on a rule according to various embodiments of the present disclosure is reported by the base station to the terminal or by a transmitting terminal to a receiving terminal through pre-defined signaling (e.g., physical layer signaling or higher layer signaling). For example, some embodiments among various embodiments of the present disclosure may be applied limitedly only to a resource allocation mode 1. For example, some embodiments among various embodiments of the present disclosure may be applied limitedly only to a resource allocation mode 2.

Hereinafter, an apparatus to which various embodiments of the present disclosure can be applied will be described.

The various descriptions, functions, procedures, proposals, methods, and/or operational flowcharts of the present disclosure described in this document may be applied to, without being limited to, a variety of fields requiring wireless communication/connection (e.g., 5G) between devices.

Hereinafter, a description will be given in more detail with reference to the drawings. In the following drawings/description, the same reference symbols may denote the same or corresponding hardware blocks, software blocks, or functional blocks unless described otherwise.

FIG. 17 shows a communication system 1, in accordance with an embodiment of the present disclosure.

Referring to FIG. 17, a communication system 1 to which various embodiments of the present disclosure are applied includes wireless devices, Base Stations (BSs), and a network. Herein, the wireless devices represent devices performing communication using Radio Access Technology (RAT) (e.g., 5G New RAT (NR)) or Long-Term Evolution (LTE)) and may be referred to as communication/radio/5G devices. The wireless devices may include, without being limited to, a robot 100 a, vehicles 100 b-1 and 100 b-2, an eXtended Reality (XR) device 100 c, a hand-held device 100 d, a home appliance 100 e, an Internet of Things (IoT) device 100 f, and an Artificial Intelligence (AI) device/server 400. For example, the vehicles may include a vehicle having a wireless communication function, an autonomous vehicle, and a vehicle capable of performing communication between vehicles. Herein, the vehicles may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). The XR device may include an Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality (MR) device and may be implemented in the form of a Head-Mounted Device (HMD), a Head-Up Display (HUD) mounted in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, etc. The hand-held device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch or a smartglasses), and a computer (e.g., a notebook). The home appliance may include a TV, a refrigerator, and a washing machine. The IoT device may include a sensor and a smartmeter. For example, the BSs and the network may be implemented as wireless devices and a specific wireless device 200 a may operate as a BS/network node with respect to other wireless devices.

The wireless devices 100 a to 100 f may be connected to the network 300 via the BSs 200. An AI technology may be applied to the wireless devices 100 a to 100 f and the wireless devices 100 a to 100 f may be connected to the AI server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. Although the wireless devices 100 a to 100 f may communicate with each other through the BSs 200/network 300, the wireless devices 100 a to 100 f may perform direct communication (e.g., sidelink communication) with each other without passing through the BSs/network. For example, the vehicles 100 b-1 and 100 b-2 may perform direct communication (e.g. Vehicle-to-Vehicle (V2V)/Vehicle-to-everything (V2X) communication). The IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b, or 150 c may be established between the wireless devices 100 a to 100 f/BS 200, or BS 200/BS 200. Herein, the wireless communication/connections may be established through various RATs (e.g., 5G NR) such as uplink/downlink communication 150 a, sidelink communication 150 b (or, D2D communication), or inter BS communication (e.g. relay, Integrated Access Backhaul (IAB)). The wireless devices and the BSs/the wireless devices may transmit/receive radio signals to/from each other through the wireless communication/connections 150 a and 150 b. For example, the wireless communication/connections 150 a and 150 b may transmit/receive signals through various physical channels. To this end, at least a part of various configuration information configuring processes, various signal processing processes (e.g., channel encoding/decoding, modulation/demodulation, and resource mapping/demapping), and resource allocating processes, for transmitting/receiving radio signals, may be performed based on the various proposals of the present disclosure.

FIG. 18 shows wireless devices, in accordance with an embodiment of the present disclosure.

Referring to FIG. 18, a first wireless device 100 and a second wireless device 200 may transmit radio signals through a variety of RATs (e.g., LTE and NR). Herein, {the first wireless device 100 and the second wireless device 200} may correspond to {the wireless device 100 x and the BS 200} and/or {the wireless device 100 x and the wireless device 100 x} of FIG. 17.

The first wireless device 100 may include one or more processors 102 and one or more memories 104 and additionally further include one or more transceivers 106 and/or one or more antennas 108. The processor(s) 102 may control the memory(s) 104 and/or the transceiver(s) 106 and may be configured to implement the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. For example, the processor(s) 102 may process information within the memory(s) 104 to generate first information/signals and then transmit radio signals including the first information/signals through the transceiver(s) 106. The processor(s) 102 may receive radio signals including second information/signals through the transceiver 106 and then store information obtained by processing the second information/signals in the memory(s) 104. The memory(s) 104 may be connected to the processor(s) 102 and may store a variety of information related to operations of the processor(s) 102. For example, the memory(s) 104 may store software code including commands for performing a part or the entirety of processes controlled by the processor(s) 102 or for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. Herein, the processor(s) 102 and the memory(s) 104 may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver(s) 106 may be connected to the processor(s) 102 and transmit and/or receive radio signals through one or more antennas 108. Each of the transceiver(s) 106 may include a transmitter and/or a receiver. The transceiver(s) 106 may be interchangeably used with Radio Frequency (RF) unit(s). In the present disclosure, the wireless device may represent a communication modem/circuit/chip.

The second wireless device 200 may include one or more processors 202 and one or more memories 204 and additionally further include one or more transceivers 206 and/or one or more antennas 208. The processor(s) 202 may control the memory(s) 204 and/or the transceiver(s) 206 and may be configured to implement the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. For example, the processor(s) 202 may process information within the memory(s) 204 to generate third information/signals and then transmit radio signals including the third information/signals through the transceiver(s) 206. The processor(s) 202 may receive radio signals including fourth information/signals through the transceiver(s) 106 and then store information obtained by processing the fourth information/signals in the memory(s) 204. The memory(s) 204 may be connected to the processor(s) 202 and may store a variety of information related to operations of the processor(s) 202. For example, the memory(s) 204 may store software code including commands for performing a part or the entirety of processes controlled by the processor(s) 202 or for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. Herein, the processor(s) 202 and the memory(s) 204 may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver(s) 206 may be connected to the processor(s) 202 and transmit and/or receive radio signals through one or more antennas 208. Each of the transceiver(s) 206 may include a transmitter and/or a receiver. The transceiver(s) 206 may be interchangeably used with RF unit(s). In the present disclosure, the wireless device may represent a communication modem/circuit/chip.

Hereinafter, hardware elements of the wireless devices 100 and 200 will be described more specifically. One or more protocol layers may be implemented by, without being limited to, one or more processors 102 and 202. For example, the one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, and SDAP). The one or more processors 102 and 202 may generate one or more Protocol Data Units (PDUs) and/or one or more Service Data Unit (SDUs) according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. The one or more processors 102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. The one or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document and provide the generated signals to the one or more transceivers 106 and 206. The one or more processors 102 and 202 may receive the signals (e.g., baseband signals) from the one or more transceivers 106 and 206 and acquire the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document.

The one or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The one or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in the one or more processors 102 and 202. The descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document may be implemented using firmware or software and the firmware or software may be configured to include the modules, procedures, or functions. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document may be included in the one or more processors 102 and 202 or stored in the one or more memories 104 and 204 so as to be driven by the one or more processors 102 and 202. The descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document may be implemented using firmware or software in the form of code, commands, and/or a set of commands.

The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, code, instructions, and/or commands. The one or more memories 104 and 204 may be configured by Read-Only Memories (ROMs), Random Access Memories (RAMs), Electrically Erasable Programmable Read-Only Memories (EPROMs), flash memories, hard drives, registers, cash memories, computer-readable storage media, and/or combinations thereof. The one or more memories 104 and 204 may be located at the interior and/or exterior of the one or more processors 102 and 202. The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 through various technologies such as wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, control information, and/or radio signals/channels, mentioned in the methods and/or operational flowcharts of this document, to one or more other apparatuses. The one or more transceivers 106 and 206 may receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document, from one or more other apparatuses. For example, the one or more transceivers 106 and 206 may be connected to the one or more processors 102 and 202 and transmit and receive radio signals. For example, the one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may transmit user data, control information, or radio signals to one or more other apparatuses. In addition, the one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may receive user data, control information, or radio signals from one or more other apparatuses. In addition, the one or more transceivers 106 and 206 may be connected to the one or more antennas 108 and 208 and the one or more transceivers 106 and 206 may be configured to transmit and receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document, through the one or more antennas 108 and 208. In this document, the one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). The one or more transceivers 106 and 206 may convert received radio signals/channels etc. from RF band signals into baseband signals in order to process received user data, control information, radio signals/channels, etc. using the one or more processors 102 and 202. The one or more transceivers 106 and 206 may convert the user data, control information, radio signals/channels, etc. processed using the one or more processors 102 and 202 from the base band signals into the RF band signals. To this end, the one or more transceivers 106 and 206 may include (analog) oscillators and/or filters.

FIG. 19 shows a signal process circuit for a transmission signal, in accordance with an embodiment of the present disclosure.

Referring to FIG. 19, a signal processing circuit 1000 may include scramblers 1010, modulators 1020, a layer mapper 1030, a precoder 1040, resource mappers 1050, and signal generators 1060. An operation/function of FIG. 19 may be performed by, without being limited to, the processors 102 and 202 and/or the transceivers 106 and 206 of FIG. 18. Hardware elements of FIG. 19 may be implemented by the processors 102 and 202 and/or the transceivers 106 and 206 of FIG. 18. For example, blocks 1010 to 1060 may be implemented by the processors 102 and 202 of FIG. 18. Alternatively, the blocks 1010 to 1050 may be implemented by the processors 102 and 202 of FIG. 18 and the block 1060 may be implemented by the transceivers 106 and 206 of FIG. 18.

Codewords may be converted into radio signals via the signal processing circuit 1000 of FIG. 19. Herein, the codewords are encoded bit sequences of information blocks. The information blocks may include transport blocks (e.g., a UL-SCH transport block, a DL-SCH transport block). The radio signals may be transmitted through various physical channels (e.g., a PUSCH and a PDSCH).

Specifically, the codewords may be converted into scrambled bit sequences by the scramblers 1010. Scramble sequences used for scrambling may be generated based on an initialization value, and the initialization value may include ID information of a wireless device. The scrambled bit sequences may be modulated to modulation symbol sequences by the modulators 1020. A modulation scheme may include pi/2-Binary Phase Shift Keying (pi/2-BPSK), m-Phase Shift Keying (m-PSK), and m-Quadrature Amplitude Modulation (m-QAM). Complex modulation symbol sequences may be mapped to one or more transport layers by the layer mapper 1030. Modulation symbols of each transport layer may be mapped (precoded) to corresponding antenna port(s) by the precoder 1040. Outputs z of the precoder 1040 may be obtained by multiplying outputs y of the layer mapper 1030 by an N*M precoding matrix W. Herein, N is the number of antenna ports and M is the number of transport layers. The precoder 1040 may perform precoding after performing transform precoding (e.g., DFT) for complex modulation symbols. Alternatively, the precoder 1040 may perform precoding without performing transform precoding.

The resource mappers 1050 may map modulation symbols of each antenna port to time-frequency resources. The time-frequency resources may include a plurality of symbols (e.g., a CP-OFDMA symbols and DFT-s-OFDMA symbols) in the time domain and a plurality of subcarriers in the frequency domain. The signal generators 1060 may generate radio signals from the mapped modulation symbols and the generated radio signals may be transmitted to other devices through each antenna. For this purpose, the signal generators 1060 may include Inverse Fast Fourier Transform (IFFT) modules, Cyclic Prefix (CP) inserters, Digital-to-Analog Converters (DACs), and frequency up-converters.

Signal processing procedures for a signal received in the wireless device may be configured in a reverse manner of the signal processing procedures 1010 to 1060 of FIG. 19. For example, the wireless devices (e.g., 100 and 200 of FIG. 18) may receive radio signals from the exterior through the antenna ports/transceivers. The received radio signals may be converted into baseband signals through signal restorers. To this end, the signal restorers may include frequency downlink converters, Analog-to-Digital Converters (ADCs), CP remover, and Fast Fourier Transform (FFT) modules. Next, the baseband signals may be restored to codewords through a resource demapping procedure, a postcoding procedure, a demodulation processor, and a descrambling procedure. The codewords may be restored to original information blocks through decoding. Therefore, a signal processing circuit (not illustrated) for a reception signal may include signal restorers, resource demappers, a postcoder, demodulators, descramblers, and decoders.

FIG. 20 shows a wireless device, in accordance with an embodiment of the present disclosure. The wireless device may be implemented in various forms according to a use-case/service (see FIG. 17).

Referring to FIG. 20, wireless devices 100 and 200 may correspond to the wireless devices 100 and 200 of FIG. 18 and may be configured by various elements, components, units/portions, and/or modules. For example, each of the wireless devices 100 and 200 may include a communication unit 110, a control unit 120, a memory unit 130, and additional components 140. The communication unit may include a communication circuit 112 and transceiver(s) 114. For example, the communication circuit 112 may include the one or more processors 102 and 202 and/or the one or more memories 104 and 204 of FIG. 18. For example, the transceiver(s) 114 may include the one or more transceivers 106 and 206 and/or the one or more antennas 108 and 208 of FIG. 18. The control unit 120 is electrically connected to the communication unit 110, the memory 130, and the additional components 140 and controls overall operation of the wireless devices. For example, the control unit 120 may control an electric/mechanical operation of the wireless device based on programs/code/commands/information stored in the memory unit 130. In addition, the control unit 120 may transmit the information stored in the memory unit 130 to the exterior (e.g., other communication devices) via the communication unit 110 through a wireless/wired interface or store, in the memory unit 130, information received through the wireless/wired interface from the exterior (e.g., other communication devices) via the communication unit 110.

The additional components 140 may be variously configured according to types of wireless devices. For example, the additional components 140 may include at least one of a power unit/battery, input/output (I/O) unit, a driving unit, and a computing unit. The wireless device may be implemented in the form of, without being limited to, the robot (100 a of FIG. 17), the vehicles (100 b-1 and 100 b-2 of FIG. 17), the XR device (100 c of FIG. 17), the hand-held device (100 d of FIG. 17), the home appliance (100 e of FIG. 17), the IoT device (100 f of FIG. 17), a digital broadcast terminal, a hologram device, a public safety device, an MTC device, a medicine device, a fintech device (or a finance device), a security device, a climate/environment device, the AI server/device (400 of FIG. 17), the BSs (200 of FIG. 17), a network node, etc. The wireless device may be used in a mobile or fixed place according to a use-example/service.

In FIG. 20, the entirety of the various elements, components, units/portions, and/or modules in the wireless devices 100 and 200 may be connected to each other through a wired interface or at least a part thereof may be wirelessly connected through the communication unit 110. For example, in each of the wireless devices 100 and 200, the control unit 120 and the communication unit 110 may be connected by wire and the control unit 120 and first units (e.g., 130 and 140) may be wirelessly connected through the communication unit 110. Each element, component, unit/portion, and/or module within the wireless devices 100 and 200 may further include one or more elements. For example, the control unit 120 may be configured by a set of one or more processors. As an example, the control unit 120 may be configured by a set of a communication control processor, an application processor, an Electronic Control Unit (ECU), a graphical processing unit, and a memory control processor. As another example, the memory 130 may be configured by a Random Access Memory (RAM), a Dynamic RAM (DRAM), a Read Only Memory (ROM)), a flash memory, a volatile memory, a non-volatile memory, and/or a combination thereof.

Hereinafter, an example of implementing FIG. 20 will be described in detail with reference to the drawings.

FIG. 21 shows a hand-held device, in accordance with an embodiment of the present disclosure. The hand-held device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch or a smartglasses), or a portable computer (e.g., a notebook). The hand-held device may be referred to as a Mobile Station (MS), a User Terminal (UT), a Mobile Subscriber Station (MSS), a Subscriber Station (SS), an Advanced Mobile Station (AMS), or a Wireless Terminal (WT).

Referring to FIG. 21, a hand-held device 100 may include an antenna unit 108, a communication unit 110, a control unit 120, a memory unit 130, a power supply unit 140 a, an interface unit 140 b, and an I/O unit 140 c. The antenna unit 108 may be configured as a part of the communication unit 110. Blocks 110 to 130/140 a to 140 c correspond to the blocks 110 to 130/140 of FIG. X3, respectively.

The communication unit 110 may transmit and receive signals (e.g., data and control signals) to and from other wireless devices or BSs. The control unit 120 may perform various operations by controlling constituent elements of the hand-held device 100. The control unit 120 may include an Application Processor (AP). The memory unit 130 may store data/parameters/programs/code/commands needed to drive the hand-held device 100. In addition, the memory unit 130 may store input/output data/information. The power supply unit 140 a may supply power to the hand-held device 100 and include a wired/wireless charging circuit, a battery, etc. The interface unit 140 b may support connection of the hand-held device 100 to other external devices. The interface unit 140 b may include various ports (e.g., an audio I/O port and a video I/O port) for connection with external devices. The I/O unit 140 c may input or output video information/signals, audio information/signals, data, and/or information input by a user. The I/O unit 140 c may include a camera, a microphone, a user input unit, a display unit 140 d, a speaker, and/or a haptic module.

As an example, in the case of data communication, the I/O unit 140 c may acquire information/signals (e.g., touch, text, voice, images, or video) input by a user and the acquired information/signals may be stored in the memory unit 130. The communication unit 110 may convert the information/signals stored in the memory into radio signals and transmit the converted radio signals to other wireless devices directly or to a BS. The communication unit 110 may receive radio signals from other wireless devices or the BS and then restore the received radio signals into original information/signals. The restored information/signals may be stored in the memory unit 130 and may be output as various types (e.g., text, voice, images, video, or haptic) through the I/O unit 140 c.

FIG. 22 shows a car or an autonomous vehicle, in accordance with an embodiment of the present disclosure. The car or autonomous vehicle may be implemented by a mobile robot, a car, a train, a manned/unmanned Aerial Vehicle (AV), a ship, etc.

Referring to FIG. 22, a car or autonomous vehicle 100 may include an antenna unit 108, a communication unit 110, a control unit 120, a driving unit 140 a, a power supply unit 140 b, a sensor unit 140 c, and an autonomous driving unit 140 d. The antenna unit 108 may be configured as a part of the communication unit 110. The blocks 110/130/140 a to 140 d correspond to the blocks 110/130/140 of FIG. 19, respectively.

The communication unit 110 may transmit and receive signals (e.g., data and control signals) to and from external devices such as other vehicles, BSs (e.g., gNBs and road side units), and servers. The control unit 120 may perform various operations by controlling elements of the vehicle or the autonomous vehicle 100. The control unit 120 may include an Electronic Control Unit (ECU). The driving unit 140 a may cause the vehicle or the autonomous vehicle 100 to drive on a road. The driving unit 140 a may include an engine, a motor, a powertrain, a wheel, a brake, a steering device, etc. The power supply unit 140 b may supply power to the vehicle or the autonomous vehicle 100 and include a wired/wireless charging circuit, a battery, etc. The sensor unit 140 c may acquire a vehicle state, ambient environment information, user information, etc. The sensor unit 140 c may include an Inertial Measurement Unit (IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, a slope sensor, a weight sensor, a heading sensor, a position module, a vehicle forward/backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illumination sensor, a pedal position sensor, etc. The autonomous driving unit 140 d may implement technology for maintaining a lane on which a vehicle is driving, technology for automatically adjusting speed, such as adaptive cruise control, technology for autonomously driving along a determined path, technology for driving by automatically setting a path if a destination is set, and the like.

For example, the communication unit 110 may receive map data, traffic information data, etc. from an external server. The autonomous driving unit 140 d may generate an autonomous driving path and a driving plan from the obtained data. The control unit 120 may control the driving unit 140 a such that the vehicle or the autonomous vehicle 100 may move along the autonomous driving path according to the driving plan (e.g., speed/direction control). In the middle of autonomous driving, the communication unit 110 may aperiodically/periodically acquire recent traffic information data from the external server and acquire surrounding traffic information data from neighboring vehicles. In addition, in the middle of autonomous driving, the sensor unit 140 c may obtain a vehicle state and/or surrounding environment information. The autonomous driving unit 140 d may update the autonomous driving path and the driving plan based on the newly obtained data/information. The communication unit 110 may transfer information about a vehicle position, the autonomous driving path, and/or the driving plan to the external server. The external server may predict traffic information data using AI technology, etc., based on the information collected from vehicles or autonomous vehicles and provide the predicted traffic information data to the vehicles or the autonomous vehicles.

The scope of the disclosure may be represented by the following claims, and it should be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalents may be included in the scope of the disclosure.

Claims in the present description can be combined in a various way. For instance, technical features in method claims of the present description can be combined to be implemented or performed in an apparatus, and technical features in apparatus claims can be combined to be implemented or performed in a method. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in an apparatus. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in a method. 

1-20. (canceled)
 21. A method for performing groupcast communication by a first apparatus, the method including: transmitting physical sidelink control channel (PSCCH) and physical sidelink shared channel (PSSCH) related to the PSCCH to N receiving apparatuses; and receiving at least one hybrid automatic repeat request (HARQ) feedback for the PSSCH based on a resource set for configuration of physical sidelink feedback channel (PSFCH) resources for the PSSCH, wherein N PSFCH resources for receiving the at least one HARQ feedback are configured among the PSFCH resources for the PSSCH based on considering M physical resource block (PRB) units and multiple code division multiplexing (CDM) codes, wherein one PRB unit among the M PRB units includes at least one PRB, and wherein the N and the M are positive integers.
 22. The method of claim 21, wherein, based on that first PSFCH resources having a first CDM code among the PSFCH resources for the PSSCH are configured on all of the M PRB units respectively, second PSFCH resources having a second CDM code among the PSFCH resources for the PSSCH are configured on at least one of the M PRB units.
 23. The method of claim 21, wherein, based on that the N is less than or equal to the M, each of the at least one HARQ feedback is received through each of other N PRB units among the M PRB units.
 24. The method of claim 23, wherein the each of the other N PRB units overlaps time resources with each other, and is adjacent to one PRB unit or two PRB units among the N PRB units on a frequency resource.
 25. The method of claim 21, wherein a part or all of the M PRB units are configured or CDM codes related to the part or all of the M PRB units are configured based on at least one of a minimum resource block (RB) index for the PSSCH, the number of RBs for the PSSCH, an RB index for the PSSCH, a source ID of the first apparatus, a slot index for the PSSCH or an index of a last PSSCH slot among a plurality of PSSCH slots related to the PSSCH linked to a slot in which a PSFCH resource related to the PSSCH is configured.
 26. The method of claim 21, wherein, based on at least one of a HARQ feedback scheme, a CDM code, or a cast type, some or all of the M PRB units are configured, or CDM codes for some or all of the M PRB units are configured.
 27. The method of claim 26, wherein the cast type includes a unicast type and a groupcast type, and wherein, based on whether the cast type is the unicast type or the groupcast type, the some or all of the M PRB units are configured, or CDM codes for the some or all of the M PRB units are configured.
 28. The method of claim 26, wherein the HARQ feedback scheme includes a NACK only feedback scheme and an ACK/NACK feedback scheme, and wherein, based on whether the HARQ feedback scheme is the NACK only feedback scheme or the ACK/NACK feedback scheme, the some or all of the M PRB units are configured, or CDM codes for the some or all of the M PRB units are configured.
 29. The method of claim 21, wherein a PSFCH resource for HARQ feedback transmitted by one of the N receiving apparatuses to the first apparatus is configured on a reception resource pool of the first apparatus or a reception resource pool of the one of the N receiving apparatuses.
 30. The method of claim 21, wherein HARQ feedback transmitted by one of the N receiving apparatuses to the first apparatus is transmitted based on synchronization derived from a synchronization source reference related to a transmission operation of the one of the N receiving apparatuses.
 31. The method of claim 21, wherein HARQ feedback transmitted by one of the N receiving apparatuses to the first apparatus is transmitted based on synchronization derived from a synchronization source reference used for the one of the N receiving apparatuses to receive the PSSCH or a synchronization source reference related to a reception resource pool in which a PSFCH resource for the one of the N receiving apparatuses is configured.
 32. A first apparatus for performing groupcast transmission, the first apparatus including: at least one memory storing instructions; at least one transceiver; and at least one processor connecting the at least one memory and the at least one transceiver, wherein the at least one processor is configured to: control the transceiver to transmit physical sidelink control channel (PSCCH) and physical sidelink shared channel (PSSCH) related to the PSCCH to N receiving apparatuses, and control the transceiver to receive at least one hybrid automatic repeat request (HARQ) feedback for the PSSCH based on a resource set for configuration of physical sidelink feedback channel (PSFCH) resources for the PSSCH, wherein N PSFCH resources for receiving the at least one HARQ feedback are configured among the PSFCH resources for the PSSCH based on considering M physical resource block (PRB) units and multiple code division multiplexing (CDM) codes, wherein one PRB unit among the M PRB units includes at least one PRB, and wherein the N and the M are positive integers.
 33. An apparatus controlling a first terminal, the apparatus including: at least one processor; and at least one computer memory that is executably connected by the at least one processor and stores instructions, wherein, by the at least one processor executing the instructions, the first terminal: transmit physical sidelink control channel (PSCCH) and physical sidelink shared channel (PSSCH) related to the PSCCH to N receiving apparatuses, and receive at least one hybrid automatic repeat request (HARQ) feedback for the PSSCH based on a resource set for configuration of physical sidelink feedback channel (PSFCH) resources for the PSSCH, wherein N PSFCH resources for receiving the at least one HARQ feedback are configured among the PSFCH resources for the PSSCH based on considering M physical resource block (PRB) units and multiple code division multiplexing (CDM) codes, wherein one PRB unit among the M PRB units includes at least one PRB, and wherein the N and the M are positive integers.
 34. The method of claim 21, wherein at least one PRB unit among the M PRB units is configured to be mapped with multiple PSFCH resources having different CDM codes based on that the N is bigger than the M, and wherein the multiple PSFCH resources are included in the resource set.
 35. The method of claim 21, wherein the number of the at least one PRB unit is L, wherein the at least one PSFCH unit is L PRB units of lowest frequencies among the M PRB units, and wherein the L is a positive integer.
 36. The method of claim 21, wherein a source identification (ID) for the first apparatus is considered in configuring the N PSFCH resources for receiving the at least one HARQ feedback.
 37. The method of claim 21, wherein each of PSFCH resources related to the at least one PRB are identified by a CDM code. 